Acetamiprid Concentration Research Articles

Development of an upconversion fluorescence DNA probe for the detection of acetamiprid by magnetic nanoparticles separation

An upconversion fluorescence DNA probe which consists of aptamer-conjugated magnet nanoparticles (apt-MNPs) and complementary DNA-conjugated upconversion nanoparticles (cDNA-UCNPs) was developed to detect acetamiprid. Acetamiprid can specifically conjugate with the apt-MNPs to dissociate the cDNA-UCNPs from the apt-MNPs and resulted in reduced fluorescence intensity through an external magnet. The change of fluorescence intensity (△I) is positively related to the concentration of acetamiprid, which can be applied for the quantification of acetamiprid. Under optimal conditions, a linear detection range and detection limit are 0.89–114.18 μg/L and 0.65 μg/L, respectively. The probe was successfully used to detect acetamiprid in spiked paddy water, soil, pear, apple, wheat and cucumber. Average recoveries are 78.2%–103.5% with intra-day relative standard deviations (RSDs) of 2.6%–10.9% and inter-day RSDs of 4.3%–10.2%. The amounts of acetamiprid in the authentic paddy water and pear samples detected by the DNA probe are significantly correlated with that detected by high-performance liquid chromatography (HPLC).

ЧУВСТВИТЕЛЬНОСТЬ ПОСТЕЛЬНЫХ КЛОПОВ (CIMEX LECTULARIUS L.) ПРИРОДНОЙ ПОПУЛЯЦИИ К АЦЕТАМИПРИДУ

The bed bug Cimex lectularius L. is a common ectoparasite in the buildings of poultry farms. There are a number of chemicals for the bed bug control, although literature data reports about insecticide-resistant populations of C. lectularius. The high efficiency of pest control on large livestock or poultry farm facilities can be achieved by the competent choice of an insecticidal formulation based on the insecticide susceptibility of insects on these farms. The aim of this work was to determine the acetamiprid susceptibility of natural population of bed bugs (Cimex lectularius L.) in a poultry farm. Tests were carried out with larvae and adults bed bugs taken from the poultry facility. The susceptibility to acetamiprid was assessed by the insect dosed contact method with lethal concentrations, which were determined by the weighted probit analysis method. The median lethal concentration of acetamiprid was 0,00000648% and its median lethal dose was 1,88 μg/g of insect weight. The acetamiprid concentration that was 4 times lower than the diagnostic one led to 100% mortality of insects. The results suggest that the natural population of bed bugs from the Company “Poultry farm Pyshminskaya” are susceptible to acetamiprid.

Neonicotinoids Detection by new LC-MS/MS Method in Romanian Surface Waters

Increasing and widespread use of neonicotinoid insecticides in all world, together with their highly toxicity to invertebrates and environmental persistence mean that surface waters need to be monitored for these compounds. In the 2015, neonicotinoid insecticides have been incorporated in the watch list of substances for a European Union monitoring program (495/2015/ EU). A new method using automated solid phase extraction (SPE) with polymeric cartridges (OASIS HLB) followed by LC-MS/MS provided good separation of the most common neonicotindoid compounds. The method was developed for the determination of four neonicotinoid insecticides (nitenpyram, thiamethoxam, clothianidin, acetamiprid) in surface water with low limit of quantification (0.3-0.9 ng/L, nanograms per liter). Recoveries in surface water samples fortified at 200 ng/L for each compound ranged from 71.4 to 109.9 %; relative standard deviation ranged from 4 to 9%. The method was applied to water samples from four streams in Romania, Danube River and its tributaries (Arges River, Jiu River, and Olt River). The surface water samples were found to be contaminated clothianidin (1.08-6.4 ng/L) and by thiamethoxam (1.1-3.8ng/L). The highest concentrations were recorded in Danube River in Oltenita point (6.4ng/L) and in Gura-Vaii point (5.5ng/L). The concentration of acetamiprid and nitenpyram were situated below limit of quantification in all samples.

DISSIPATION RATE AND RESIDUES OF ACETAMIPRID AND IPRODIONE IN SWEET CHERRY FRUITS

A neonicotinoid insecticide acetamiprid and dicarboximide fungicide iprodione,are used in sweet cherry for control of the major pest (Rhagoletis cerasi L.) andpathogen (Monilia laxa). For the purpose of the safe consumption of agriculturalproducts after pesticide application, studies on their dissipation kinetics areessential to work out their half-lives (DT50) and pre-harvest intervals (PHI).However, there is a lack of information on the persistence of acetamiprid andiprodione in sweet cherry fruits in different climatic conditions of production.Therefore, the objectives of this study were to investigate the dissipation andresidues of acetamiprid and iprodione in sweet cherry fruits, as well as to evaluatethe validity of prescribed PHI for these pesticides. Field experiments wereconducted in a sweet cherry orchard, near Novi Sad, where acetamiprid andiprodione were applied at a recommended concentration. At various time intervals,from treatment to harvest, having in mind PHI (14 days for acetamiprid and 7 daysfor iprodione) representative samples of sweet cherry fruits were collected.Extraction of pesticides was carried out by QuEChERS method, followed byHPLC-DAD analysis. The method was validated in accordance with theSANCO/12571/2013 document and was used the determination of pesticides inreal sweet cherry samples. During the study period, the concentration ofacetamiprid and iprodione decreased from 0.52 mg/kg to 0.11 mg/kg and from 0.29mg/kg to 0.07 mg/kg, respectively. The dissipation of acetamiprid and iprodioneresidues over the time fitted to the equation Ct=0.52-0.22t and Ct=0.29-0.20t, with DT50of 3.15 and 3.47 days, respectively. Finally, the content of acetamiprid andiprodione in sweet cherry samples, at the end of PHI, were below the maximumallowed level specified by the Serbian (1.5 mg/kg and 3 mg/kg) and EU MRLs (1.5mg/kg and 10 mg/kg).

Acetamiprid Accumulates in Different Amounts in Murine Brain Regions.

Neonicotinoids such as acetamiprid (ACE) belong to a new and widely used single class of pesticides. Neonicotinoids mimic the chemical structure of nicotine and share agonist activity with the nicotine acetylcholine receptor (nAchR). Neonicotinoids are widely considered to be safe in humans; however, they have recently been implicated in a number of human health disorders. A wide range of musculoskeletal and neuromuscular disorders associated with high doses of neonicotinoids administered to animals have also been reported. Consequently, we used a mouse model to investigate the response of the central nervous system to ACE treatment. Our results show that exposure to ACE-containing water for three or seven days (decuple and centuple of no observable adverse effect level (NOAEL)/day) caused a decrease in body weight in 10-week old A/JJmsSlc (A/J) mice. However, the treatments did not affect brain histology or expression of CD34. ACE concentrations were significantly higher in the midbrain of ACE-treated mice than that of the normal and vehicle groups. Expression levels of α7, α4, and β2 nAChRs were found to be low in the olfactory bulb and midbrain of normal mice. Furthermore, in the experimental group (centuple ACE-containing water for seven days), β2 nAChR expression decreased in many brain regions. Information regarding the amount of accumulated ACE and expression levels of the acetylcholine receptor in each region of the brain is important for understanding any clinical symptoms that may be associated with ACE exposure.

Effect and interaction study of acetamiprid photodegradation using experimental design.

The methodology of experimental research was carried out using the MODDE 6.0 software to study the acetamiprid photodegradation depending on the operating parameters, such as the initial concentration of acetamiprid, concentration and type of the used catalyst and the initial pH of the medium. The results showed the importance of the pollutant concentration effect on the acetamiprid degradation rate. On the other hand, the amount and type of the used catalyst have a considerable influence on the elimination kinetics of this pollutant. The degradation of acetamiprid as an environmental pesticide pollutant via UV irradiation in the presence of titanium dioxide was assessed and optimized using response surface methodology with a D-optimal design. The acetamiprid degradation ratio was found to be sensitive to the different studied factors. The maximum value of discoloration under the optimum operating conditions was determined to be 99% after 300 min of UV irradiation.

Acetamiprid multidetection by disposable electrochemical DNA aptasensor

In this work, we propose an electrochemical DNA aptasensor for sensitive multidetection of acetamiprid based on a competitive format and disposable screen-printed arrays. To improve the sensitivity of the aptasensor, polyaniline film and gold nanoparticles were progressively electrodeposited on the graphite screen-printed electrode surface by cyclic voltammetry. Gold nanoparticles were then employed as platform for thiol-tethered DNA aptamer immobilization. Different acetamiprid solutions containing a fixed amount of biotinylated complementary oligonucleotide sequence by DNA aptasensor arrays were analyzed. Streptavidin-alkaline phosphatase conjugate was then added to trace the affinity reaction. The enzyme catalyzed the hydrolysis of 1-naphthyl phosphate to 1-naphthol. The enzymatic product was detected by differential pulse voltammetry. A decrease of the signal was obtained when the pesticide concentration was increased, making the sensor work as signal off sensor. Under optimized conditions by testing key experimental parameters, a dose-response curve was constructed between 0.25 and 2.0µM acetamiprid concentration range and a limit of detection of 0.086µM was calculated. The selectivity of the aptasensor was also confirmed by the analysis of atrazine pesticide. Finally, preliminary experiments in fruit juice samples spiked with acetamiprid were also performed.

Aptamer contained triple-helix molecular switch for rapid fluorescent sensing of acetamiprid

In this study, an aptamer-based fluorescent sensing platform using triple-helix molecular switch (THMS) was developed for the pesticide screening represented by acetamiprid. The THMS was composed of two tailored DNA probes: a label-free central target specific aptamer sequence flanked by two arm segments acting as a recognition probe; a hairpin-shaped structure oligonucleotide serving as a signal transduction probe (STP), labeled with a fluorophore and a quencher at the 3′ and 5′-end, respectively. In the absence of acetamiprid, complementary bindings of two arm segments of the aptamers with the loop sequence of STP enforce the formation of THMS with the “open” configuration of STP, and the fluorescence of THMS is on. In the presence of target acetamiprid, the aptamer-target binding results in the formation of a structured aptamer/target complex, which disassembles the THMS and releases the STP. The free STP is folded to a stem loop structure, and the fluorescence is quenched. The quenched fluorescence intensity was proportional to the concentration of acetamiprid in the range from 100 to 1200nM, with the limit of detection (LOD) as low as 9.12nM. In addition, this THMS-based method has been successfully used to test and quantify acetamiprid in Chinese cabbage with satisfactory recoveries, and the results were in full agreement with those from LC-MS. The aptamer-based THMS presents distinct advantages, including high stability, remarkable sensitivity, and preservation of the affinity and specificity of the original aptamer. Most importantly, this strategy is convenient and generalizable by virtue of altering the aptamer sequence without changing the triple-helix structure. So, it is expected that this aptamer-based fluorescent assay could be extensively applied in the field of food safety inspection.

Aptamer-based Resonance Light Scattering for Sensitive Detection of Acetamiprid.

In this work, an aptasensor-based resonance light-scattering (RLS) method was developed for the sensitive and selective detection of acetamiprid. The ABA (acetamiprid binding aptamer)-stabilized gold nanoparticles (ABA-AuNPs) were used as a probe. Highly specific single-strand DNA (ssDNA, i.e, aptamers) that bind to acetamiprid with high affinity were employed to discriminate other pesticides, such as edifenphos, kanamycin, metribuzin et. al. The sensing approach is based on a specific interaction between acetamiprid and ABA. Aggregation of AuNPs was specifically induced by the desorption of the ABA from the surface of AuNPs, which caused the RLS signal intensity to be enhanced at 700 nm. The alteration of AuNPs' aggregation has been successfully optimized by controlling several conditions. Under the optimal conditions, the RLS intensity changes (I/I0) of AuNPs were linearly correlated with the acetamiprid concentration in the range of 0 - 100 nM. The detection limit is 1.2 nM (3σ). This method had also been used for acetamiprid detection in lake water samples.

Resonance energy transfer from CdTe quantum dots to gold nanorods using MWCNTs/rGO nanoribbons as efficient signal amplifier for fabricating visible-light-driven “on-off-on” photoelectrochemical acetamiprid aptasensor

To develop novel resonance energy transfer (RET) system can provide opportunities for the goal of sensitive and inexpensive detection of aptamer-related targets such as DNA and microRNA, protein, and small-molecule. In this work, a novel RET system from CdTe quantum dots (QDs) to Au nanorods (Au NRs) was fabricated, by employing MWCNTs/reduced graphene oxide nanoribbons (MWCNTs/rGONRs) as the photoelectrochemical (PEC) signal amplifier and ideal support for QDs anchored. The photocurrent signal of CdTe QDs was amplified for ∼3.3-fold due to the sensitization effect of MWCNTs/rGONRs, and the proposed CdTe-MWCNTs/rGONRs exhibited the typical fluorescence emission at 713nm, which showed good spectral overlap with the UV–vis absorption spectrum of Au NRs. Furthermore, a visible-light-driven “on-off-on” PEC sensing strategy for sensitive and selective determination of acetamiprid was designed. Under optimal conditions, the resulting PEC aptasensor was found to be linearly proportional to the logarithm of target acetamiprid concentration in the range from 0.5pM to 10μM with a detection limit of 0.2pM. Moreover, the proposed sensor displayed high selectivity and good reproducibility, and has been successfully applied in the direct detection of acetamiprid in real food samples. This method could resist environmental interfering agents and be extended for sensitive and reliable detection of a wide range of analytes in complex samples.

Design and evaluation of an apta-nano-sensor to detect Acetamiprid in vitro and in silico

Pesticide detection is a main concern of food safety experts. Therefore, it is urgent to design an accurate, rapid, and cheap test. Biosensors that detect pesticide residues could replace current methods, such as HPLC or GC-MC. This research designs a biosensor based on aptamer (Oligonucleotide ss-DNA) in the receptor role, silver nanoparticles (AgNPs) as optical sensors and salt (NaCl) as the aggregative inducer of AgNPs to detect the presence of Acetamiprid. After optimization, .6 μM aptamer and 100 mM salt were employed. The selectivity and sensitivity of the complex were examined by different pesticides and different Acetamiprid concentrations. To simulate in vitro experimental conditions, bioinformatics software was used as in silico analysis. The results showed the detection of Acetamiprid at the .02 ppm (89.8 nM) level in addition to selectivity. Docking outputs introduced two loops as active sites in aptamer and confirmed aptamer–Acetamiprid bonding. Circular dichroism spectroscopy (CD) confirmed upon Acetamiprid binding, aptamer was folded due to stem-loop formation. Stability of the Apt–Acetamiprid complex in a simulated aqueous media was examined by molecular dynamic studies.

Fabricating a novel label-free aptasensor for acetamiprid by fluorescence resonance energy transfer between NH2-NaYF4: Yb, Ho@SiO2 and Au nanoparticles

Rare earth-doped upconversion nanoparticles have promising potential in the field of pesticide detection because of their unique frequency upconverting capability and high detection sensitivity. This paper reports a novel aptamer-based nanosensor for acetamiprid detection using fluorescence resonance energy transfer (FRET) between NH2-NaYF4: Yb, Ho@SiO2 (UCNPs) and gold nanoparticles (GNPs). Herein, GNPs as acceptors efficiently quench the fluorescence of UCNPs and acetamiprid specifically interacts with acetamiprid binding aptamer (ABA), causing the conformation changes of ABA from random coil to hairpin structure. Accordingly, ABA no longer stabilizes the GNPs in salt solution, leading to the varying aggregation extent of GNPs. Thus, the fluorescence of UCNPs are proportionally recovered. Under the optimized conditions, the enhancement efficiency was observed to increase linearly with the concentration of acetamiprid from 50nM to 1000nM, resulting in a relatively low limit of 3.2nM. Additionally, the aptasensor demonstrated high selectivity to similar structure pesticides such as imidacloprid and chlorpyrifos, and further confirmed its application capacity in adulterated tea samples.

Turn-on sensor for quantification and imaging of acetamiprid residues based on quantum dots functionalized with aptamer

In this paper, a novel turn-on sensor was constructed for quantification and imaging of acetamiprid. Acetamiprid aptamer-modified ZnS:Mn probe (ZnS:Mn-Aptamer) was obtained by conjugating ZnS:Mn QDs with acetamiprid binding aptamer. The fluorescence of the probe was turn off by multi-walled carbon nanotubes (MWCNTs) based on fluorescence resonance energy transfer (FRET) between ZnS:Mn-Aptamer and MWCNTs. After acetamiprid was introduced, the fluorescence was turn on because ZnS:Mn-Aptamer specifically binded with acetamiprid. Based on the above-mentioned principle, the quantitative detection and imaging of acetamiprid in real samples were achieved. The linear equation could be described as F/F0=1.101+0.0312CA (CA represented the concentration of acetamiprid, nM) in a linear range of 0–150nM with a detection limit of 0.7nM. The results suggested this method had remarkable sensitivity, selectivity, and was very simple without complex operation. Meanwhile, this novel turn-on sensor has the potential of in situ visual determination for pesticide residues in complex system.

A sensitive and label-free photoelectrochemical aptasensor using Co-doped ZnO diluted magnetic semiconductor nanoparticles.

Co-doped ZnO diluted magnetic semiconductor as a novel photoelectric beacon was first constructed for photoelectrochemical (PEC) aptasensor of acetamiprid. The fabricated PEC sensing is based on the specific binding of acetamiprid and its aptamer, which induces the decreasement of enhanced photocurrent produced by the electron donor of quercetin. Co(2+) doping has a beneficial effect in extending the band width of light absorption of ZnO into the visible region and to promote the separation of the photoinduced carriers due to the sp-d exchange interactions existing between the band electrons and the localized d electrons of Co(2+). The fabricated aptasensor was linear with the concentration of acetamiprid in the range of 0.5-800 nmolL(-1) with the detection limit of 0.18 nmolL(-1). The presence of same concentration of other conventional pesticides did not interfere in the detection of acetamiprid and the recovery is between 96.2% and 103.7%. This novel PEC aptasensor has good performances with high sensitivity, good selectivity, low cost and portable features. The strategy of Co-doped ZnO diluted magnetic semiconductor paves a new way to improve the performances of PEC aptasensor.

A novel sensor for the detection of acetamiprid in vegetables based on its photocatalytic degradation compound

An electrochemical method for the indirect determination of acetamiprid was studied, using titanium dioxide photocatalysts coupled with a carbon paste electrode. The cyclic voltammetric results indicated that the photocatalytic degradation compound of acetamiprid had electroactivity in neutral solutions. The amount of acetamiprid was further indirectly determined by differential pulse anodic stripping voltammetric analysis as a sensitive detection technique. The experimental parameters were optimized with regard to the photocatalytic degradation time, pH of buffer solution, accumulation potential and accumulation time. Under optimal conditions, the proposed electrochemical method could detect acetamiprid concentrations ranging from 0.01 to 2.0μM, with a detection limit (3S/N) of 0.2nM. Moreover, the proposed method displays excellent selectivity, good reproducibility, and acceptable operational stability and can be successfully applied to acetamiprid determination in vegetable samples with satisfying results.

Impact of Acetamiprid Toxicity on Lactate Dehydrogenase in Some Tissues of the Fish Oreochromis mossambicus

Experiment was conducted on fish, Oreochromis mossambicus to study the effect of acetamiprid on tissue biomarker lactate dehydrogenase. Acetamiprid is a neonicotinoid pesticide and it is used by the farmers to protect their crops. This pesticide residue reaches to the aquatic ecosystem by many ways and affects the aquatic fauna. Lethal Concentration (LC 50 ) of acetamiprid for O. mossambicus has been calculated by probit analysis and recorded as 5.99 ppm at 96 h. Chronic exposure shows increased activity of LDH in liver, brain and gill tissues during all the exposure periods when compared with the control. This significant increase in enzyme activity was observed due to toxic effect of acetamiprid. Long term exposure of organisms to pesticides means a continuous health hazard for the fish population and it is on high risk by consuming these toxicated fishes.

Removal of imidacloprid and acetamiprid from tea infusions by microfiltration membrane

SummaryRemoval of imidacloprid and acetamiprid in tea infusions by microfiltration membrane using dead‐end model was investigated in the present study. The results showed that microfiltration significantly promoted the removal of both pesticides (P < 0.05) in tea infusions. Furthermore, the extent of removal was strongly influenced by the pore size of membrane, operational pressure and the concentrations of tea infusions. The initial concentration of imidacloprid and acetamiprid showed no significant effect on their removal rates. The maximum removal rates were 79.7% for imidacloprid and 81.9% acetamiprid. The changes in major chemical components of tea infusions after microfiltration were evaluated. The results indicated that microfiltration caused no considerable changes in total polyphenols and total free amino acids, and small but statistically significant losses (6.3–18.0%) of eight catechins and three methylxanthines when filtration volume reached to 200 mL. The present study validated the application of microfiltration as a potentially feasible and promising method for the removal of imidacloprid and acetamiprid residues from tea infusions.

The Effects of Neonicotinoids on the Longevity of the Male and Female Populations of Drosophila melanogaster

Most of the pesticides applied in various areas around the world and in our country are known to affect non-targeted organisms causing their death. For this reason, a new class of pesticides specific only for the targeted organism that does not harm the others is needed. Neonicotinoids, known as insecticide classes, have been used since 1980 to meet this requirement. In this study, Imidacloprid and Acetamiprid, commonly used neonicotinoids in pest management, were investigated for their chronic effects on the longevity of Drosophila melanogaster. Both insecticides were added to the Standard Drosophila Medium at different doses (0.5, 1.0, 1.5, and 2.0 ppm). The male and female individuals of the wild type D. melanogaster Oregon R were chronically exposed to the insecticides in these application groups. It was determined that the mean lifespan of the female and male D. melanogaster populations decreased with the increasing concentrations of Imidacloprid and Acetamiprid in comparison to the control group. When the maximum and average lifespan values of the control and application groups were compared, the difference was found to be statistically significant with p<0.05.

Toxicopathological changes on Wistar rat after multiple exposures to acetamiprid

Aim: To see the toxicopathological changes after multiple exposure to acetamiprid (ACP) and also to obtain more information regarding the manner in which ACP acts at cellular level. Materials and Methods: A subacute toxicity study of ACP was undertaken in 72 female Wistar rats in four groups (18 each). Three different concentrations of ACP (25, 100 and 200 mg/kg of body weight) were administered orally to rats. Untreated rats served as control. Different plasma enzyme and analytes were measured. Gross and histopathological observations were noted in this experiment. Result: There was a significant increase in the plasma enzymes tested in this experiment. There was a significant decrease in plasma glucose, cholesterol and low-density lipid. Necrotic and degenerative changes were observed in vital organs. Conclusion: It is observed that ACP has the toxic potential (on liver, kidney, heart, ovary and brain) at sub lethal doses.

A facile label-free colorimetric aptasensor for acetamiprid based on the peroxidase-like activity of hemin-functionalized reduced graphene oxide

A facile aptasensor has been developed for the colorimetric detection of acetamiprid by using the hemin-functionalized reduced graphene oxide (hemin-rGO) composites. The as-prepared hemin-rGO composites possessed both the ability of rGO to physically adsorb the aptamers and the peroxidase-like activity of hemin that could catalyse 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2, to produce a solution with blue color. The well-dispersed hemin-rGO composites coagulated completely at the proper salt concentration; however, the coagulation of hemin-rGO was vanished when abundant aptamers were adsorbed on its surface because the attached negatively charged DNA backbone increased individual hemin-rGO electrostatic repulsion. In the detection scheme, acetamiprid with different concentrations was firstly incubated with the same amount of aptamer. The more acetamiprid in the tested solution, the less free aptamers were absorbed on the hemin-rGO surface, making the composites coagulate to a higher degree in the presence of the optimum NaCl concentration. As a consequence, the content of hemin-rGO in the supernatant was decreased after centrifugation, which catalysed oxidation of TMB in the presence of H2O2 to produce light blue color with a low absorbance. The color variation relavant to the acetamiprid concentration can be judged by the naked eyes and easily monitored by the inexpensive UV–vis spectrometer. Such designed aptasensor displayed a linear response for acetamiprid in the range from 100nM to 10μM with a detection limit of 40nM (S/N=3). This colorimetric aptasensing platform offers great advantages including the simple operation process, low-cost portable instrument, and user-friendly applications.