Acetamiprid Concentration Research Articles

Electrochemical assay of acetamiprid in vegetables based on nitrogen-doped graphene/polypyrrole nanocomposites.

Dual-mode electrochemical aptasensor based on nitrogen-doped graphene (NG) doped with the conducting polymer polypyrrole (PPy) nanocomposite is proposed for the determination of acetamiprid. NG/PPy was electrodeposited onto the glassy carbon electrode (GCE) using cyclic voltammetry technique. NG/PPy/GCE showed outstanding electrocatalytic activity for the oxidation of nitrite due to "active region" induced by the charge redistribution of carbon atoms. The ultrasensitive dual-mode biosensor for acetamiprid could be easily developed by coupling acetamiprid aptamers with the NG/PPy hybrid. The specific binding between acetamiprid and the aptamers resulted in the increase of differential pulse voltammetry (DPV) signal change and the decrease of chronoamperometry (CA) signal, and the concentration of acetamiprid could be measured. The working potentials of DPV and CA were - 0.2 ~ 0.4V and - 0.4 ~ 0.4V (vs. SCE), respectively. The dual-mode acetamiprid biosensor showed a wide linear range from 10-12 to 10-7gmL-1, with low detection limits of 1.15 × 10-13gmL-1 and 7.32 × 10-13gmL-1 through DPV and CA modes, respectively. Moreover, owing to high active area and superior conductivity, as well as good electrocatalytic ability, the dual-sensing platform based on NG/PPy nanocomposite supported the quantification of acetamiprid in complex samples. A dual-mode electrochemical aptasensor based on NG/PPy nanocomposite for acetamiprid detection was proposed through both the increase of differential pulse voltammetry (DPV) signal change and the decrease of chronoamperometry (CA) signal of the nitrite oxidation electrocatalyzed by NG/PPyn in sensors and biosensors.

Electrochemical determination of acetamiprid using PEDOT sensing coating functionalized with carbon quantum dots and Prussian blue nanoparticles.

A dual-mode electrochemical biosensor for acetamiprid detection was proposed for the first timebased on carbon quantum dots/Prussian blue (CQDs/PB)-functionalized poly(3,4-ethylenedioxythiphene) (PEDOT) nanocomposite. The nanocomposite with spherical stacking nanostructure showed high surface area, excellent catalytic ability, and cycling stability. The biosensor can be effortlessly constructed after the immobilization of acetamiprid aptamer. The concentration of acetamiprid can be determined by differential pulse voltammetry (DPV) based on its signal change deduced from the pristine PB. With the capture of acetamiprid, the response current (I-T) signal generated by hydrogen peroxide catalysis from the biosensor can also been used to establish the method for monitoring acetamiprid. The dual-mode biosensor showed a wide linear range from 10-12gmL-1 to 10-6gmL-1, low detection limits of 6.84 × 10-13gmL-1 and 4.99 × 10-13gmL-1, and ultrafast detection time of 25s and 5s through DPV and I-T mode, respectively. The biosensor possessed excellent selectivity and stability. More importantly, the biosensor was successfully applied to detect acetamiprid residues in vegetables, proving a promising approach for routine detection of pesticide in real samples. The biosensor based on PEDOT/CQDs/PB for acetamiprid can be effortlessly constructed through both the increase of differential pulse voltammetry (DPV) signal change deduced by the pristine PB and the decrease of the response current (I-T) signal of the reduction of hydrogen peroxide catalyzed by PEDOT/CQDs/PB.

A simple mesoporous silica Nanoparticle-based aptamers SERS sensor for the detection of acetamiprid

In this study, we developed a novel, rapid, simple, and sensitive nano sensor based on the controlled release of 4-Aminothiophenol (4-ATP) signal molecules from aptamers (Apts) modified aminated mesoporous silica nanoparticles (MSNs-NH2) for the quantitative detection of acetamiprid (ACE). Firstly, we synthesized the positively charged MSNs-NH2 by one-pot method, then loaded 4-ATP signal molecules into the pore, and finally electrostatically adsorbed the Apts onto the MSNs-NH2, which acts as a gate to control the release of signal molecules. When ACE is added to the system, ACE preferentially and specifically binds to Apts, so the gate opens and 4-ATP signal molecules are released from the pore. Meanwhile, the silver-loaded mesoporous silica nanoparticles (Ag@SiO2) were prepared by one-pot method as surface-enhanced Raman spectroscopy (SERS) substrate to amplify the signal. The intensity of 4-ATP signal molecules at 1433 cm−1 position was observed to has a linear relationship with the concentration of ACE by SERS detection. Under the optimized detection conditions, a linear correlation was observed in the range of 5–60 ng/mL (R2 = 0.99749), and the limit of detection (LOD) was 2.66 ng/mL. The method has high sensitivity, good selectivity and reproducibility, and can be used for actual sample analysis with the recovery rate of 96.24–103.6 %. This study provides a reference for the rapid and convenient detection of ACE in agricultural products.

Experimental and theoretical investigation of acetamiprid adsorption on nano carbons and novel PVC membrane electrode for acetamiprid measurement

Acetamiprid removal was investigated by synthesized Graphene oxide, multiwall nanotube and graphite from an aqueous solution. For this propose, FT-IR, XRD, UV–Vis, SEM and EDS were used to characterize the synthesized nano adsorbents and to determine the removal process. A novel PVC membrane electrode as selective electrode made for determining the concentration of acetamiprid. Batch adsorption studies were conducted to investigate the effect of temperature, initial acetamiprid concentration, adsorbent type and contact time as important adsorption parameters. The maximum equilibrium time was found to be 15 min for graphene oxide. The kinetics studies showed that the adsorption of acetamiprid followed the pseudo-second-order kinetics mechnism. All the adsorption equilibrium data were well fitted to the Langmuir isotherm model and maximum monolayer adsorption capacity 99 percent. Docking data of adsorption have resulted in the same as experimental data in good manner and confirmed the adsorption process.

Insight into the toxic effects, bioconcentration and oxidative stress of acetamiprid on Rana nigromaculata tadpoles

Pesticide pollution has been identified as a factor in the amphibian population decrease. Acetamiprid is a common neonicotinoid pesticide that poses a risk to amphibians due to its high water solubility and inability to be digested. However, there is little research on acetamiprid's toxicity in amphibians, particularly on its biochemical toxic effects. In this study, we investigated the acute toxicity, bioenrichment-elimination, biochemical parameters and metabolism of acetamiprid in Rana nigromaculata tadpoles. The results indicated that acetamiprid is harmful to Rana nigromaculata tadpoles, with an LC50 = 18.49 mg L−1 of 96 h for acute toxicity. Acetamiprid showed rapid accumulation and low bioconcentration levels in tadpoles, with bioconcentration factors (BCFs) < 1. In the elimination process, the concentration of acetamiprid decreased rapidly, with the elimination half-life t1/2 values < 1 d. Additionally, oxidative stress was observed in tadpoles, with biochemical parameters such as superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) being significantly altered. Nontargeted metabolomics revealed significant changes in biomolecules such as lipids, organic acids and nucleotides in tadpoles, and these metabolites influence pathways including serine and threonine metabolism, histidine metabolism, linoleic acid metabolism and sphingolipid metabolism. These results indicate that acetamiprid caused toxic effects on Rana nigromaculata tadpoles. Our study provides a better understanding of the fate and risk of acetamiprid in amphibians, as well as guidelines for its rational use.

On-site rapid and simultaneous detection of acetamiprid and fipronil using a dual-fluorescence lab-on-fiber biosensor

Adual-fluorescence lab-on-fiber biosensor was developed for the rapid and simultaneous on-site determination of acetamiprid and fipronil, based on time-resolved effect and indirect competitive immunoassay principle. The optical fiber modified with two hapten-protein conjugates servesas a bifunctional bio-probe. The dual-color fluorescent reporters were prepared via labeling acetamiprid and fipronil antibodies with Cy5.5 and Alexa Fluor 555, which were excited at 635-nm and 520-nm laserwavelengths, respectively. In the presence of targets, the binding sites of corresponding antibodies were occupied and less antibodies were connected to the probe surface, resulting in the reduction of fluorescence signal. The concentration of acetamiprid and fipronil was determined by measuring the fluorescence signals at 568nm and 702nm (emission wavelengths), respectively. Under optimal conditions, the linear response range was 14.2-225.4ng/L for acetamiprid and 25.1-162.8ng/L for fipronil, and the limit of detection was 6.51ng/L and 17.8ng/L for acetamiprid and fipronil, respectively. The method was successfully applied to the simultaneous detection of acetamiprid and fipronil in three environmental samples, and the recoveries were between 90 and 128%. The dual-fluorescence lab-on-fiber biosensor provides a feasible platform for simultaneous and rapid detection of multiple pesticide residues. A dual-fluorescence lab-on-fiber biosensor was developed for the rapid and simultaneous on-site determination of acetamiprid and fipronil. A bifunctional bio-probe was prepared from the optical fiber modified with two hapten-protein conjugates. Acetamiprid and fipronil antibodies were labeled with different fluorophores and used as dual-color fluorescent reporters.

Differences in the Sublethal Effects of Sulfoxaflor and Acetamiprid on the Aphis gossypii Glover (Homoptera: Aphididae) Are Related to Its Basic Sensitivity Level.

Simple SummaryThe sublethal effects of insecticides are not only environmentally risky to arthropods but may also promote resistance evolution. Sublethal effects are influenced by factors such as the type of insecticide, sublethal concentration, and type of pest. This study evaluated the sublethal effects of sulfoxaflor and acetamiprid on two field cotton aphid (Aphis gossypii) populations with different genetic backgrounds. For acetamiprid, a significant negative sublethal effect of an LC25 concentration of acetamiprid on longevity and fecundity was observed in the F0 generation of Jinghe, and a significant negative sublethal effect occurred in the F1 and F2 generations of Yarkant, some biological traits of which were significantly degraded. However, in terms of biological traits, significant stimulative sublethal effects of an LC25 concentration of sulfoxaflor were observed in the F0 generation of Jinghe and the F1 generation of Yarkant. These experimental results demonstrate that sulfoxaflor and acetamiprid have different sublethal effects on A. gossypii that vary depending on the generation. Moreover, the sublethal effects of an insecticide may be influenced by the genetic background and resistance levels of A. gossypii. Our findings are useful for assessing the overall effects of sulfoxaflor and acetamiprid on A. gossypii.The cotton aphid, Aphis gossypii, is an important insect pest of many crops around the world, and it has developed resistance to a large number of frequently used insecticides. The sublethal effects of insecticides not only have an environmental risk to arthropods but also have the potential to promote resistance evolution. The sublethal effects (inhibitory or stimulatory) are influenced by many factors, such as the type of insecticide, sublethal concentrations, pest species, and others. In this study, the sublethal effects of sulfoxaflor and acetamiprid on A. gossypii were compared using two field-collected populations. The results show that sulfoxaflor was more toxic than acetamiprid against A. gossypii in both populations, the LC50 concentrations of acetamiprid and sulfoxaflor were 6.35 and 3.26 times higher, respectively, for the Jinghe population than for Yarkant. The LC25 concentration of acetamiprid significantly reduced adult longevity and fecundity in exposed adults (F0) of the Jinghe population, but it had no significant effects on these factors in Yarkant. Similar inhibitory effects were found in the F1 and F2 generations, but the biological traits in the Yarkant population were significantly reduced when the parents (F0) were exposed to LC25 of acetamiprid, whereas the changes in the Jinghe population were not significant. However, sublethal sulfoxaflor showed a stimulatory effect on A. gossypii in the F0 and F1 generation; the adult fecundity and longevity of the F0 generation were significantly higher in Jinghe, while the biological traits of the F1 generation were obviously higher in Yarkant. In the F2 generation, the r and λ were significantly higher in Jinghe; meanwhile, these biological traits were reduced in Yarkant. These results indicate that sulfoxaflor and acetamiprid had different sublethal effects on A. gossypii that varied by generation. In addition, we speculate that the genetic background and the resistance levels of A. gossypii may also influence the sublethal effects. Our findings are useful for assessing the overall effects of sulfoxaflor and acetamiprid on A. gossypii.

Dual-Mode electrochemical biosensors based on Chondroitin sulfate functionalized polypyrrole nanowires for ultrafast and ultratrace detection of acetamiprid pesticide

The inappropriate and excessive use of pesticides poses a great challenge to human health. It is necessary to analyze pesticide residues efficiently, economically and quickly to minimize the risk of public safety issues. Herein, a dual-mode biosensor was proposed for ultrafast and ultratrace detection of acetamiprid (ACE). The polypyrrole nanowires (PPyNWs) was prepared using the guidance of CS by electrochemical method, which showed large electroactive surface area, excellent conductivity and high stability. After immobilization of ACE aptamer onto CS/PPyNWs, the biosensor can be effortlessly prepared. The ACE concentration can be measured by both the signal decrease of the chronocoulometry (CC) method and the chronoamperometry (CA) method. The dual-mode biosensor exhibited ultrafast detection speeds of 0.5 s and 2 s across 9 and 6 orders of magnitude linear ranges through CC and CA, respectively. More importantly, the biosensor was successfully applied to detect ACE residues in soil samples, proving the feasibility of the dual-mode biosensor for ACE detection in complex samples.

Exploratory analysis of the associations between neonicotinoids and measures of adiposity among US adults: NHANES 2015–2016

BackgroundToxicology studies suggest that neonicotinoids may be associated with adiposity development via thyroid hormone disruption and increased oxidative stress. Prior epidemiological studies report mixed results for the association between neonicotinoids and adiposity measures. ObjectiveTo examine the association between detectable concentrations of parent neonicotinoids (imidacloprid, acetamiprid, clothianidin) and neonicotinoid metabolites (5-hydroxy-imidacloprid, N-desmethyl-acetamiprid) with adiposity measures among US adults, and whether sex modifies the associations for neonicotinoid metabolites with adiposity. MethodsNational Health and Nutrition Examination Survey (NHANES) 2015–2016 data was utilized to estimate covariate-adjusted associations between detectable neonicotinoids and fat mass index (FMI), lean mass index (LMI), waist circumference, body fat percentage, and body mass index (BMI) using multiple linear regression. We estimated incidence rate ratios (IRRs) for overweight or obese status with detectable neonicotinoid concentrations using Poisson's modified regression. Sampling strategies were accounted for in the regression models. ResultsDetectable levels of acetamiprid were associated with a decrease in FMI (β = −3.17 kg/m2, 95% CI [-4.79, −1.54]), LMI (β = −3.17 kg/m2, 95% CI [-5.17, −1.17]), body fat percentage (β = −4.41, 95% CI [-8.20, −0.62]), waist circumference (β = −9.80 cm, 95% CI [-19.08, −0.51]), and BMI (β = −3.88kg/m2, 95% CI [-7.25, −0.51]) among adults. In contrast, detectable levels of 5-hydroxy-imidacloprid were associated with greater rates of being overweight/obese (IRR = 1.11, 95% CI [1.04, 1.18)) and increased LMI (β = 0.67 kg/m2, 95% CI [0.04, 1.29]). Sex modified the association between N-desmethyl-acetamiprid and LMI (pint = 0.075) with a positive association among males (β = 1.14 kg/m2, 95% CI [0.38, 1.90]), and an insignificant inverse association in females. Sex also modified the association for N-desmethyl-acetamiprid with FMI (pint = 0.095) and body fat percentage (pint = 0.072), with suggestive evidence showing positive associations for males and inverse associations for females. ConclusionDetectable concentrations of acetamiprid were inversely associated with adiposity, while there were mixed findings for 5-hydroxy-imidacloprid. Findings suggest sex differences, though results are not clear with regard to the directionality of the association by sex.

Single and joint toxicity assessment of acetamiprid and thiamethoxam neonicotinoids pesticides on biochemical indices and antioxidant enzyme activities of a freshwater fish Catla catla

Neonicotinoids pesticides are extensively used in many countries due to their high insect selectivity. Acetamiprid and thiamethoxam are the neonicotinoids most commonly detected in the aquatic environment. This work examined the single and joint toxicity of acetamiprid and thiamethoxam in a freshwater fish Catla catla. Fish were exposed to acetamiprid (0.5 mg/L and 1 mg/L), thiamethoxam (0.01 mg/L and 0.5 mg/L) and their binary mixtures (0.5 mg/L of acetamiprid and 0.01 mg/L of thiamethoxam) for 96 h. The stress biomarkers such as glucose, protein, electrolytes, Na+/K+ -ATPase and oxidative stress were evaluated. Among the biochemical parameters, plasma protein, electrolytes (sodium, potassium and chloride) and gill ATPase activity were decreased in response to individual and binary mixtures treatments. In contrast, blood glucose level showed significant increase in all the treatments. Exposure to various concentrations of acetamiprid and thiamethoxam resulted in significant decrease in superoxide dismutase (SOD) activity in the gill tissue. However, SOD activity was significantly elevated during binary mixtures treatment. Glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST) and reduced glutathione (GSH) levels in gills were decreased significantly after individual and binary mixtures treatments. Fish exposed at individual and binary mixtures significantly elevated the level of LPO in gill tissue. Our findings suggest that multi-biomarker approach can be effectively used to assess the effects of joint toxicity of pesticides and to monitor the neonicotinoids pesticides in the aquatic environment.

Electrochemical Oxidation Approach towards the Treatment of Acetamiprid Pesticide from Polluted Water

Introduction: Acetamiprid (AP) is one of the most widely used pesticides in the neonicotinoid class. AP residues in the environment have received considerable due to their potential toxicity to humans. Therefore, it is important to remove AP from the aqueous solution.&#x0D; Materials and Methods: In the current study, response surface methodology (RSM) was used as an efficient approach to optimize the removal of AP using the electro-Fenton (EF) process. The effects of the main variables, including reaction time, AP concentration, current density, and H2O2 dosage were investigated and optimized. ANOVA technique was also used to identify the Fisher’s value (F-value) and P-value of the model.&#x0D; Results: The predicted AP removal efficiency by the model was in good agreement with the obtained experimental results with correlation regression of 0.9885. The ANOVA test proved that the developed quadratic model was significant with very low P-values less than 0.05, the high F-value of 240.1, and regression coefficients close to 1 at a 95% confidence level. The optimum condition for AP removal efficiency of 99.02% was attained at the reaction time of 12 min, AP concentration of 3.5 mg L-1, the current density of 12 mA cm-2, and H2O2 dosage of 86 µL.&#x0D; Conclusion: RSM was employed as a suitable method to optimize the operating condition and maximize the AP removal. Herein, the EF process as an eco-friendly electrochemical advanced oxidation process (EAOP) successfully applied to remove AP from the water and wastewater.

Detection of Acetamiprid by Aptamer Based on a Porous Silicon Microcavity

In this paper, a new method for pesticide detection based on porous silicon microcavities was proposed. First, the aptamer of acetamiprid was fixed in the functionalized porous silicon microcavity. Then, the complementary strand of the aptamer modified with graphene quantum dots was hybridized with the aptamer, and the effective refractive index of the porous silicon microcavity increased. When acetamiprid was added, it bound to the aptamer due to its stronger specificity. The aptamer separated from the complementary strand of the coupled graphene quantum dots and bound to acetamiprid, resulting in a decrease in the effective refractive index, and its central wavelength of reflection spectrum was blue shifted, and the blueshift increased with the increase of acetamiprid concentration. The relationship between the change in central wavelength and the concentration of acetamiprid was analysed, and the detection limit of acetamiprid was 151 nm.

Effects of Acetamiprid at Low and Median Lethal Concentrations on the Development and Reproduction of the Soybean Aphid Aphis glycines.

Simple SummaryWe conducted a study on the effects of LC50 and LC30 acetamiprid on the growth and development of the soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae). We found that exposure to acetamiprid at LC50 significantly extended the mean generation time, adult pre-ovipositional period, and total pre-reproduction period compared to the control, whereas exposure to acetamiprid at LC30 significantly shortened these periods. Acetamiprid at LC50 treatment significantly decreased the growth rate compared with the LC30 treatment. In addition, this study also found that low lethal concentration of acetamiprid could advance the occurrence of a reproductive peak, which could help us understand the major occurrence period of soybean aphids under acetamiprid stress. The present study provides reference data that could facilitate the exploration of the effects of acetamiprid on A. glycines in the field.The soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae) is a major pest of soybean and poses a serious threat to soybean production. Studies on the effect of acetamiprid on the life table parameters of A. glycines, provide important information for the effective management of this pest. We found that exposure to acetamiprid at LC50 significantly extended the mean generation time, adult pre-reproductive period, and total pre-reproduction period compared with the control, whereas exposure to acetamiprid at LC30 significantly shortened these periods. Exposure to acetamiprid at both LC30 and LC50 significantly decreased the fecundity of the female adult, net reproductive rate, intrinsic rate of increase, and finite rate of increase compared with the control. The probability of attaining the adult stage was 0.51, 0.38, and 0.86 for a newly born nymph from the LC30 acetamiprid treatment group, LC50 acetamiprid treatment group, and control group, respectively. Acetamiprid at both LC50 and LC30 exerted stress effects on A. glycines, with the LC50 treatment significantly decreased the growth rate compared with the LC30 treatment. The present study provides reference data that could facilitate the exploration of the effects of acetamiprid on A. glycines in the field.

Intensification of degradation of acetamiprid by the combination of ultrasonic cavitation with other advanced oxidation processes (AOPs)

The degradation of acetamiprid has been studied using ultrasonic cavitation (US) and its combination with H2O2, Fenton's reagents and photo-Fenton process. Initially, the optimization of operational parameters has been carried out to enhance the performance of US. Maximum degradation of acetamiprid was obtained at ultrasonic power density of 0.22 ​W/mL, operating pH of 2.5 and acetamiprid concentration of 10 ​ppm. Further, the rate of degradation of acetamiprid obtained by US (0.807 ​× ​10-3 min-1) was intensified by combining it with hydrogen peroxide (4.925 ​× ​10-3 min-1), Fenton's reagent (5.593 ​× ​10-3 min-1) and photo-Fenton process (39.907 ​× ​10-3 min-1) with synergistic coefficients of 5.58, 3.14 and 2.04 respectively. The comparison of US and various US based combined processes have been carried out on the basis of mineralization study and cavitational yield. Maximum extent of mineralization of 52.25% and cavitational yield of 5.288 ​× ​10-12 ​mol/J were observed for US ​+ ​photo-Fenton process. Further, the cost of electricity of 4.128 USD/L and power consumption of 41.650 ​kWh/L obtained in the case of US has significantly reduced to 0.233 USD/L and 2.358 ​kWh/L respectively for US ​+ ​photo-Fenton process. The study of effect of radical scavenger (sodium bicarbonate) has confirmed that degradation of acetamiprid using US based combined processes is controlled by OH• radical attack. Comparison of cavitational yield, power consumption and cost of electricity of US and US based combined processes has indicated US ​+ ​photo-Fenton process to be the most energy efficient and cost effective process for the degradation of acetamiprid.

A fluorescent aptasensor based on gold nanoparticles quenching the fluorescence of rhodamine B to detect acetamiprid.

Pesticide residue detection is one of the main safety issues in the utilization of medicinal plants. In this work, a highly selective and sensitive aptasensor for acetamiprid determination was designed. The mechanism of the proposed method is based on the fluorescence resonance energy transfer (FRET) between gold nanoparticles (AuNPs) and rhodamine B (RB). Aptamers protect AuNPs from salt-induced aggregation, which causes fluorescence quenching of RB by the AuNPs via surface energy transfer. In the absence of acetamiprid, AuNPs were coated with aptamers on the surface and dispersed in NaCl solution. At this time, the dispersed AuNPs could perfectly quench the fluorescence intensity of RB. In contrast, in the presence of acetamiprid, aptamers specifically combine with acetamiprid to form a complex. With a high salt concentration, AuNPs would be aggregated without aptamer protection, weakening the RB quenching effect. Therefore, the concentration of acetamiprid could be obtained from the change in fluorescence intensity in the system. A fluorescent sensing method was established with a linear range from 0.1 to 3 μg mL-1, and the LOD was 0.0285 μg mL-1. The recoveries of acetamiprid in traditional Chinese medicine (TCM) samples were 96.23-105.75%. This method has great application value for the detection of acetamiprid in a complex sample matrix.

A review on material analysis of food safety based on fluorescence spectrum combined with artificial neural network technology

Aiming at the problem that it is difficult to achieve rapid and accurate detection of pesticide residues, the artificial neural network method is used to separate the mixed fluorescence spectra in the measurement of acetamiprid pesticide residues, and a fluorescence spectrum that can quickly detect the pesticide residues of acetamiprid on solid surfaces is designed. According to the back-propagation algorithm, the three-layer artificial neural network principle is used to detect the acetamiprid residue in the mixed system of acetamiprid and filter paper with severely overlapping fluorescence spectra. In the range of 340nm~400nm, using the fluorescence intensity values ​​at 20 characteristic wavelengths as the characteristic network parameters, after network training and testing, the recovery rates of acetamiprid concentrations of 40mg/kg and 90mg/kg are 102% and 97%, respectively. The relative standard deviations of the determination results were 1.4% and 1.9%, respectively. The experimental results show that the BP neural network-assisted fluorescence spectroscopy method for the determination of acetamiprid pesticide residues on filter paper has the characteristics of fast network training, short detection period, and high measurement accuracy.

A Simple and Novel Sensor for the Determination of Acetamiprid Based on Its Reducing Effect on the Chemiluminescence of S, N-CQDs in CH3CN-H2O2 System.

A simple and novel method for the determination of acetamiprid in water samples is suggested. The method is based on the reducing effect of acetamiprid on the chemiluminescence intensity of new sulfur and nitrogen co-doped carbon dots (S, N-CQDs) in an acetonitrile-hydrogen peroxide (CH3CN-H2O2) system. The possible mechanism was investigated, and it was found that S, N-CQDs react with (1O2)2*, produced from the CH3CN-H2O2 reaction, leading to excited state S, N-CQDs, which deactivate to the ground state by photon emission. Acetamiprid diminishes the chemiluminescence (CL) intensity by competing with S, N-CQDs. The CL intensity reduction is proportional to the concentration of acetamiprid. S, N-CQDs were easily prepared by a hydrothermal method. Under the optimal conditions, a linear range of 2.5 - 25.0 μg L-1 with a detection limit (3σ) of 0.4 μg L-1 was obtained. This method was successfully applied to the determination of trace amounts of residual pesticides in water samples.

Facile Detection and Quantification of Acetamiprid Using a Portable Raman Spectrometer Combined with Self-Assembled Gold Nanoparticle Array

Rapid and facile determination of pesticides is critically important in food and environmental monitoring. This study developed a self-assembled gold nanoparticle array based SERS method for highly specific and sensitive detection of acetamiprid, a neonicotinoid pesticide that used to be difficult in SERS analysis due to its low affinity with SERS substrates. SERS detection and quantification of acetamiprid was conducted with self-assembled gold nanoparticle arrays at the interface of chloroform and water as the enhancing substrate. Since targets dissolved in chloroform (organic phase) also have access to the hot-spots of Au NP array, the developed method exhibited good sensitivity and specificity for acetamiprid determination. Under the optimal conditions, SERS intensities at Raman shifts of 631 cm−1 and 1109 cm−1 displayed a good linear relationship with the logarithm concentration of acetamiprid in the range of 5.0 × 10−7 to 1.0 × 10−4 mol/L (0.11335 ppm to 22.67 ppm), with correlation coefficients of 0.97972 and 0.97552, respectively. The calculated LOD and LOQ of this method were 1.19 × 10−7 mol/L (0.265 ppb) and 2.63 × 10−7 mol/L (0.586 ppb), respectively, using SERS signal at 631 cm−1, and 2.95 × 10−7 mol/L (0.657 ppb) and 3.86 × 10−7 mol/L (0.860 ppb) using SERS signal at 1109 cm−1, respectively. Furthermore, the developed SERS method was successfully applied in determining acetamiprid on the surface of apple and spinach. This method offers an exciting opportunity for rapid detection of acetamiprid and other organic pesticides considering its advantages of simple preparation process, good specificity and sensitivity, and short detection time (within 1 h).

Removal of the neonicotinoid insecticide acetamiprid from wastewater using heterogeneous photocatalysis

ABSTRACT Due to its high solubility in water, a large amount of the neonicotinoid insecticide acetamiprid persisting in the soil of treated crops enters surface water or groundwater. The aim of this study was to investigate the photocatalytic degradation of acetamiprid in an aqueous medium. The experiments were carried out in an annular suspension reactor operating in recirculated batch mode and using a UV-A lamp as the radiation source. An appropriate modification of the commercial TiO2-P25 photocatalyst was carried out to reduce its band gap energy and electron–hole recombination as well as to extend the visible light range of TiO2. The photodegradation study was carried out using a three-factor two-stage Box–Behnken experimental design to investigate the main effects and interactions between the operating variables, such as solution pH, initial concentration of acetamiprid, and amount of photocatalyst. The efficiency of the processes was determined by high performance liquid chromatography. The first-order pseudo-reaction kinetic model, as a simplification of the models of Langmuir–Hinshelwood under conditions of relatively low acetamiprid concentration, was applied and the reaction rate constants were estimated. The results of the study showed that the initial concentration of the pollutant was the most influential factor for the photocatalytic degradation process. Using ANOVA analysis, a linear model was established to predict the system behaviour at different operating conditions. The highest conversion and rate constant of acetamiprid degradation were recorded in the experiment with the lowest tested concentration of acetamiprid (2 mg/L), the average concentration of photocatalyst (60 mg) and at pH 8.

A fluorescence and localized surface plasmon resonance dual-readout sensing strategy for detection of acetamiprid and organophosphorus pesticides

In this work, a fluorescence/localized surface plasmon resonance (Fluorescence/LSPR) dual-readout sensing system that using DNA functionalized gold nanoparticles (AuNPs) as nanoprobe was designed for acetamiprid (ACE) and organophosphorus pesticides (OPs) detection. The ACE detection was based on the fluorescence resonance energy transfer (FRET) between fluorochrome Cy3-labeled aptamer and AuNPs of nanoprobe. The high specificity of ACE allowed Cy3-labeled aptamer to release from nanoprobe, resulting in a significantly fluorescence recovery related to the concentration of ACE. On the other hand, the strategy for OPs detection relied on the acetylcholinesterase (AChE)-mediated oxidative polymerization blocking of dopamine on AuNPs surface and the inhibition of OPs toward AChE. The degree of polymerization of dopamine depended on the concentration of OPs, which led to a tremendous LSPR spectral shift and scattering color change of nanoprobe. The dual-readout sensing system showed great sensitivity and selectivity for ACE and OPs (used chlorpyrifos as model) with a detection limit of 166.7 pg mL−1 and 0.17fgmL−1, respectively. Moreover, two distinct color changes could be visual recognized to indicate the content of ACE and OPs, which was considered to be a conceivable way for pesticides residues assay. Therefore, this work paved a new avenue for rapid detection of multi-pesticides via a Fluorescence/LSPR dual signal response and visual screening, and hold great potential for noxious substance monitoring.