Detection Of Chloramphenicol Research Articles

Multilayered Fe3O4@(ZIF-8)3 combined with a computer-vision-enhanced immunosensor for chloramphenicol enrichment and detection

The misuse and overuse of chloramphenicol poses severe threats to food safety and human health. In this work, we developed a magnetic solid-phase extraction (MSPE) pretreatment material coated with a multilayered metal–organic framework (MOF), Fe3O4 @ (ZIF-8)3, for the separation and enrichment of chloramphenicol from fish. Furthermore, we designed an artificial-intelligence-enhanced single microsphere immunosensor. The inherent ultra-high porosity of the MOF and the multilayer assembly strategy allowed for efficient chloramphenicol enrichment (4.51 mg/g within 20 min). Notably, Fe3O4 @ (ZIF-8)3 exhibits a 39.20% increase in adsorption capacity compared to Fe3O4 @ZIF-8. Leveraging the remarkable decoding abilities of artificial intelligence, we achieved the highly sensitive detection of chloramphenicol using a straightforward procedure without the need for specialized equipment, obtaining a notably low detection limit of 46.42 pM. Furthermore, the assay was successfully employed to detect chloramphenicol in fish samples with high accuracy. The developed immunosensor offers a robust point-of-care testing tool for safeguarding food safety and public health.

Enhancing electrochemiluminescence for chloramphenicol detection based on the synergistic effect of doped Ti3C2 with ultrasound

Chloramphenicol (CAP) is known to be harmful to the environment and food, posing a threat to human health. Developing an effective and convenient method for detecting CAP is crucial. An electrochemiluminescence (ECL) biosensor has been designed for sensitive detection of CAP. The improved ECL behavior was attributed to the synergistic effect of N and P co-doped Ti3C2-Apt1 (N, P-Ti3C2-Apt1) nanoprobes and high intensity focused ultrasound (HIFU) pretreatment. The doping of N and P could improve the electrochemical performance of Ti3C2. HIFU pretreatment generated more reactive oxygen species (ROS) in the luminol-O2 system. N, P-Ti3C2 could aggregate and catalyze ROS, causing an increase in ECL intensity. Furthermore, N, P-Ti3C2 as a carrier loaded more aptamer, which could recognize CAP with high specificity. The detection limit was 0.01 ng/mL. This biosensor has been successfully applied in milk and environmental water samples, highlighting its potential in the field of food and environmental analysis.

Dense pyridine nitrogen as surface decoration of interwoven Cu-MOFs for chloramphenicol-specific electrochemical sensor

The detection of chloramphenicol (CAP), a strictly prohibited antibiotic in veterinary drugs, remains challenging owing to its specific-sensing requirements. However, achieving a specific sensing strategy is crucial and requires the design of high-performance materials. In this study, a stable, double-interpenetrated dual-wall cage-in-cage metal–organic framework (MOF), SXNU-3-Cu ({[Cu2(INA)2(TATB)]·H2O}n), was designed using a mixed-linker strategy that incorporated the ligands of 4,4,4,-s-triazine-2,4,6-triyltribenzonic acid (H3TATB) and isonicotinic acid (HINA). Owing to their high connectivity and double-interpenetrated structure, the SXNU-3-Cu MOFs exhibited excellent thermal stability, as well as resistance to water and pH changes. The SXNU-3-Cu/ACET/GCE electrochemical sensor demonstrated a wide linearity range from 0.03 to 0.1 μM and 0.3–70 μM, with an impressive CAP detection limit of 9.51 nM. In particular, the interaction between –NO2 in CAP and dense pyridine nitrogen of HINA ligand enhanced the adsorption of CAP on the surface of the cage via Van der Waals forces. Subsequently, targeted oxidation–reduction catalytic reactions occurred inside accessible copper sites against nitro groups in the CAP molecules, resulting in high sensitivity and specific sensing towards CAP. Furthermore, we conducted comprehensive experimental and theoretical investigations to verify the sensing mechanism between the SXNU-3-Cu MOFs and CAP molecules. We determined that Cu-based MOFs have significant potential for drug monitoring and biochemical analyses.

Catalytic hairpin self-assembly amplification fluorescence detection of chloramphenicol based on cross-shaped DNA and UiO-66

A catalytic hairpin self-assembly (CHA) amplification method was developed for CAP detection based on cross-shaped DNA and UiO-66. MOF was used to quench the fluorescent signal of FAM labeled DNA. Cross-shaped DNA with four fluorophore group (FAM) was utilized to enhance the fluorescent intensity. CAP could open hairpin structure of H-apt and induce CHA reaction. The product of CHA hybridized with cross-shaped DNA, resulting its leaving from the surface of UiO-66 and recovery of fluorescent signal. The limit of detection (LOD) was low to 0.87 pM. This method had been successfully applied for the detection of CAP in actual samples. Importantly, the high sensitivity was attributed to the great amplification efficiency of CHA, strong fluorescent intensity of cross-shaped DNA structure and great fluorescent quenched efficiency of UiO-66.

Facile synthesis of sub-10 nm Cu-MOF nanofibers as electrochemical sensor element for picomolar chloramphenicol detection

Precise detection of antibiotics in aquatic environments is significant for human health and ecological environment development due to the excessive use of antibiotics. However, the accurate detection of ultralow-level antibiotics, such as picomolar level, has always been an extremely challenging task. Herein, we synthesized the sub-10 nm copper-based metal–organic framework nanofibers (Cu-MOF NFs) with a large specific area and high conductivity for achieving the electrochemical detection of picomolar-level chloramphenicol (CAP) in real water samples. As a result, by optimization of synthesis time and detection conditions, Cu-MOF NFs with a diameter of about 5 nm exhibited the ultralow limit of detection with 0.03 pM and wide detection range with 0.1––1.0 × 106 pM for CAP detection, as well as the designed sensor electrode has the excellent specificity, reproducibility, and stability. Importantly, the prepared sensor electrode exhibits reliable analytical results for CAP in real water samples, such as tap water, bottled water, and milk, indicating that designed sensor electrode has great application potential for the precise detection of antibiotics in practical samples.

Highly sensitive and selective electrochemical sensor for the determination of chloramphenicol

Recently, there has been significant interest in the utilization of indium-doped cadmium sulfide (CdS) for the detection of chloramphenicol (CAP) in food samples due to its exceptional performance. The objective of this research is to develop a simple, rapid, and highly sensitive sensor for CAP detection. CdS possesses remarkable characteristics as a semiconductor material, including a large specific surface area, abundant pore structure, and excellent electrical conductivity. The electrochemical properties of glassy carbon electrodes (GCE) were comprehensively investigated both in their pristine state and when modified with CdS/GCE, CdIn2S4/GCE, Cd1.5In2S4.5/GCE, and Cd2In2S5/GCE. The surface areas of the modified electrodes CdIn2S4/GCE, Cd1.5In2S4.5/GCE, and Cd2In2S5/GCE were measured to be 0.08 cm2, 0.097 cm2, and 0.25 cm2, respectively. Five replicate samples using the optimized proportioned electrode Cd2In2S5/GCE resulted in a response error below 5%. These results indicate that the composite demonstrates exceptional conductivity and reproducibility while maintaining satisfactory sensitivity and high specificity. The proposed sensor based on Cd2In2S5/GCE exhibited an impressive dynamic linear range from 10 nmol/L to 20 μmol/L with an exceptionally low detection limit of 3.8 nmol/L and remarkable sensitivity of 0.38 μA μm−1 cm−2. This sensor successfully quantified CAP in water samples with a satisfactory recovery rate ranging from 99.5% to 100.3%, accompanied by an RSD below 7.6%. Consequently，this developed electrochemical sensor presents itself as the optimal choice for simultaneous determination of CAP in both food and water samples.

A reagent-based label free electrochemiluminescence biosensor for ultrasensitive quantification of low-abundant chloramphenicol

Today, great attentions have been attracted on chloramphenicol (CAP) to its nonnegligible biotoxicity to human. It is most important and urgent to quantify the low-abundant chloramphenicol by generating simple and efficient analysis approach for the detection of chloramphenicol. Herein, we proposed a novel reagent-based label free electrochemiluminescence (ECL) biosensor based on AuNPs@CoFe-PBA nanomaterials as highly efficient catalysts for luminol/hydrogen peroxide (H2O2) system and target indirectly induced activation of the CRISPR/Cas 12a amplification system for simple and efficient quantification of the low-abundant chloramphenicol. Typically, AuNPs@CoFe-PBA nanomaterials as a novel catalyst for luminol/H2O2 system were enclosed in the X-type DNA hydrogel to greatly inhibit their catalytic performance due to the blocking effect of DNA hydrogel. In presence of target CAP, it induced DNA structure transformation of the aptamer of chloramphenicol to generate a toehold to present catalyzed hairpin assembly (CHA) amplification with the help of two self-designed hairpin structure DNA to perform the hybridizer of the two hairpins, which could activate the CRISPR/Cas 12a system to carry out the DNA cleavage. Its activity breaks the structure of DNA hydrogels and releases AuNPs@CoFe-PBA nanomaterials, which enhances the ECL signals of the luminol/H2O2 systems for simple and sensitive analysis of chloramphenicol. Most importantly, all of the target induced amplifications were performed in the detection solution and the ECL reactions were generated on the bare electrode without any modification to construct a reagent-based label-free analysis system simply with high efficiency for quantification of the low-abundant chloramphenicol. The results showed that there was a good linear relationship between ECL intensity and CAP concentration in range from 10 pg/mL to 1 ug/mL with a detection limit of 7.75 pg/mL, providing great potentials to quantify the low-abundant chloramphenicol and some other biomarkers for early disease diagnosis, food safety testing and environmental analysis.

Quantitative detection of chloramphenicol residue in fish based on SERS aptasensor coupled with magnetic separation

Chloramphenicol (CAP) is a widely used antibiotic in aquaculture. However, its improper use and the resulting residues in fish have become a significant concern for human health. Conventional methods for quantifying CAP are complex and expensive, leading to the need for more efficient and sensitive techniques. In this study, both CAP aptamer and sulfhydryl (SH) complementary DNA strand (SH-cDNA) were bound to gold and silver core–shell nanoparticles (Ag@Au CSNPs) and core–shell magnetic nanoparticles (Fe3O4@Au MNPs) via Au-S covalent bonding and were used as SERS signal probes and capture probes, respectively. The principle of aptamer competitive recognition was applied to achieve the quantitative detection of CAP in fish. The capture probe and the signal probe generated strong signals by complementary hybridization in the absence of CAP in the detection system. In the presence of CAP, the CAP aptamer bonded to the CAP, and the signal probe was separated from the capture probe, resulting in a linear decrease in SERS signal intensity. Consequently, there was a strong inverse relationship between SERS intensity and the logarithm of CAP concentration, ranging from 10-5 to 10-1 µg·mL−1 (R2 = 0.9974). The limit of detection (LOD) was as low as 16 pg·mL−1. The established method exhibited strong selectivity, anti-interference, reproducibility, and stability.

Self-powered photoelectrochemical sensing for sensitive detection of chloramphenicol based on sulfur-vacancy engineered MoS2 nanoribbons/plasmonic Ti3C2 MXene with continual injection of photoinduced electrons

Accurate detection of antibiotic concentration in a matrix is vital for determining the contamination status. In this study, we have developed an ultrasensitive self-powered photoelectrochemical (PEC) sensor based on MoS2/Ti3C2 heterojunction, where sulfur vacancy engineered MoS2 nanoribbons were first grown in situ onto the plasmonic Ti3C2 MXene via a facile thermal treatment method. With the introduction of nonmetallic plasmonic Ti3C2, the constructed MoS2/Ti3C2 heterostructure facilitated the continuous photoelectron injection from MoS2 to Ti3C2 MXene, resulting in stable surface plasmon resonance (SPR) effect and enhanced photoelectric conversion. Compared to MoS2 alone, the PEC response of as-prepared MoS2/Ti3C2 heterojunction was increased by five times. Due to the excellent PEC properties of the MoS2/Ti3C2 heterostructure, a new ultrasensitive PEC aptasensor was fabricated with the assistance of chloramphenicol (CAP) aptamer. The developed aptasensor displayed satisfactory stability over a period of 11 days and high selectivity, a wide linear response range (0.1 nM to 0.01 mM) and a low detection limit (0.034 nM). Therefore, it can be successfully applied to CAP detection in environmental samples. This work provided a signal amplification strategy to fabricate efficient self-powered PEC sensing platforms.

Carbon-dots encapsulated luminescent metal–organic frameworks@surface molecularly imprinted polymer: A facile fluorescent probe for the determination of chloramphenicol

In this study, carbon dots (CDs)-encapsulated luminescent metal–organic frameworks@surface molecularly imprinted polymer (CDs@MOF@SMIP) was facilely prepared and applied as fluorescent probe for specific identification and sensitive detection of chloramphenicol (CAP) in food. Fluorescent CDs, serving as signal tags, were encapsulated within metal–organic backbones (ZIF-8), yielding luminescent MOF materials (CDs@ZIF-8). The synthesized CDs, CDs@ZIF-8 and CDs@ZIF-8@SMIP were investigated by morphological and structural characterizations (UV–Vis, XRD, FT-IR, BET, TEM). The CDs@ZIF-8@SMIP probe was demonstrated to have remarkable selectivity and sensitivity towards CAP. Its fluorescence decreased linearly with CAP concentration from 0.323 μg L-1 (0.001 μM) to 8075.0 μg L-1 (25.0 μM), featuring a low detection limit of 0.08 μg L-1. The CDs@ZIF-8@SMIP-based fluorescence strategy achieved satisfactory recoveries (95.5 % − 101.0 %) in CAP-spiked commercial foods with RSD < 4.4 % (n = 3). These results indicate that this method can effectively detect trace CAP in food matrices and has broad application prospects.

Design of MXene-Based Multiporous Nanosheet Stacking Structures Integrating Multiple Synergistic SERS Enhancements for Ultrasensitive Detection of Chloramphenicol.

Motivated by the desire for more sensitivity and stable surface-enhanced Raman scattering (SERS) substrates to trace detect chloramphenicol due to its high toxicity and ubiquity, MXene has attracted increasing attention and is encountering the high-priority task of further observably improving detection sensitivity. Herein, a universal SERS optimization strategy that incorporates NH4VO3 to induce few-layer MXenes assembling into multiporous nanosheet stacking structures was innovatively proposed. The synthesized Nb2C-based multiporous nanosheet stacking structure can achieve a low limit of detection of 10-10 M and a high enhancement factor of 2.6 × 109 for MeB molecules, whose detection sensitivity is improved by 3 orders of magnitude relative to few-layer Nb2C MXenes. Such remarkably enhanced SERS sensitivity mainly originates from the multiple synergistic contributions of the developed physical adsorption, the chemical enhancement, and the conspicuously improved electromagnetic enhancement arising from the intersecting MXenes. Furthermore, the improved SERS sensitivity endows Nb2C-based multiporous structures with the capability to achieve ultrasensitive detection of chloramphenicol with a wide linear range from 100 μg/mL to 1 ng/mL. We believe it is of great significance in conspicuously developing the SERS sensitivity of other MXenes with surficial negative charges and has a great promising perspective for the trace detection of other antibiotics in microsystems.

Antenna effect enhanced ECL immunoassay using microfloral europium porphyrin coordination polymers based on Eu3+ and TCPP for the detection of chloramphenicol in foods.

The "antenna effect" is one of the most important energy transfer modes in lanthanide light-emitting polymers. In this study, novel luminescent nanostructured coordination polymers (Eu-PCP) were synthesized in one step using Eu3+ as the central metal ion and 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP) as the organic ligand. The unique "antenna effect" observed between Eu3+ and TCPP leads to a substantial improvement in the electrochemiluminescence (ECL) emission efficiency. Eu-PCP exhibits good cathodic ECL characteristics. Additionally, Au@SnS2 nanosheets exhibit favorable electrical conductivity, biocompatibility, and a significant specific surface area. This makes them a suitable choice as substrate materials for the modification of electrode surfaces and capturing antigens. Being well known, the development of sensitive and rapid methods to detect chloramphenicol is essential for food safety. Based on this, we report a novel competitive electrochemiluminescence immunoassay to achieve ultra-sensitive and highly specific detection of chloramphenicol. The linear range was 0.0002-500 ng mL-1 and the detection limit was 0.09 pg mL-1. Apart from that, the experimental results proved that it provided a new analytical tool for the detection of antibiotic residues in food safety.

Novel nickel(II) phthalocyanine/reduced graphene oxide: an electrochemical sensing platform for analysis of hydroquinone and chloramphenicol in environmental samples.

Novel tetra-2-(biphenyl-4-yl)-1,3-benzoxazol-carboxamide nickel(II) phthalocyanine (NiTBPBXCAPc) and rGO were confirmed using FT-IR, UV-vis, XRD, TGA and Raman spectra. The NiTBPBXCAPc and rGO nanocomposite has been developed to detect hydroquinone (HQN) and chloramphenicol (CPC). NiTBPBXCAPc has been examined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) analysis. The simultaneous CV analysis of HQN and CPC demonstrated the ability of NiTBPBXCAPc@rGO/GCE to execute simultaneous redox reactions. The voltammetric and amperometric limit of detection for HQN and CPC was determined to be 4.5 and 3.5 nM respectively, with a sensitivity of 0.446 and 0.416 μA M-1 cm-2. The amperometric LOD was observed to be 5 and 4 nM with a sensitivity of 0.235 and 0.288 μA M-1 cm-2. Additionally, the NiTBPBXCAPc@rGO/GC electrode is also used for real sample analysis with outstanding recovery. The long-term storage stability, reusability, and real-world sample analysis of the NiTBPBXCAPc@rGO/GC electrode demonstrated its use in environmental analysis.

A sensitive sandwich-type electrochemical aptasensing platform based on Ti3C2Tx/MoS2/MWCNT@rGONR composites for simultaneous detection of kanamycin and chloramphenicol in food samples.

A Ti3C2Tx/MoS2/MWCNT@rGONR nanocomposite was prepared for the first time for building a sensitive electrochemical aptasening platform to simultaneously detect kanamycin (Kana) and chloramphenicol (Cap). Owing to their accordion-like structure, rich surface groups, and high charge mobility, Ti3C2Tx/MoS2/MWCNT@rGONR composites provided a spacious covalent immobilization surface and a better electrochemical aptasensing platform. The aptamers of Kana and Cap used in sensors enhance the selectivity. Furthermore, TiP, an ion exchanger, was used for loading more different metal ions functioning as labels to form a sandwich-type sensor together with Ti3C2Tx/MoS2/MWCNT@rGONR, improving the electrochemical sensitivity and obtaining a highly distinguishable signal readout. Under the optimized conditions, the sensor has good detection limits of 0.135 nmol L-1 and 0.173 nmol L-1 for Kana and Cap, respectively, at the same linearity concentration of 0.5-2500 nmol L-1. Finally, it was successfully applied for detection in milk and fish meat, and the results were compared with the standard method HPLC, indicating its great potential for food safety monitoring.

Nitrogen doped biomass derived carbon and BiVO4 composite for simultaneous detection of furazolidone and chloramphenicol

An efficient electrochemical sensor based on nitrogen functionalized biochar (N-BC) and BiVO4 hybrid nanocomposites was prepared, and used for simultaneous detection of furazolidone (FZD) and chloramphenicol (CAP) with highly sensitive and selective in food sample. The N-BC was obtained by acid activation method which using biomass waste (rice halls) as the raw and processed material and urea as the nitrogen source, which was further mixed with BiVO4 to synthesized N-BC/BiVO4 composite. The surface morphology and structured properties were characterized by Scanning electron microscopic (SEM), Nitrogen (N2) adsorption/desorption isotherms, X-ray powder diffraction (XRD) patterns, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The cyclic voltammetry (CV) and electrochemical impedance studies of N-BC/BiVO4 film on GCE showed that electron transfer rate in [Fe (CN)6]3−/4− solution was rapider than bare GCE, N-BC/GCE and BiVO4/GCE. The sensor was successfully used for the detection of FZD and CAP with wide linear ranges of 0.1–1600 μM for FZD and 0.1–3200 μM for CAP, low limit of detection of 0.053 μM for FZD and 0.087 μM for CAP (S/N = 3), respectively. In addition, the proposed sensor has shown good anti-interference ability, reproducibility and stability, and obtained satisfactory results for respective or simultaneous detection of FZD and CAP in milk sample.

A sensitive signal off photoelectrochemical aptasensor based on CuO nanosheets @Au nanoflowers for the detection of chloramphenicol

A signal off type photoelectrochemical (PEC) aptasensor was constructed for the sensitive detection of chloramphenicol based on CuO nanosheets (CuO NSs) and gold nanoflowers (Au NFs) modified indium tin oxide (ITO) electrode. CuO NSs was p-type photoactive semiconductor materials, which had narrow band gap and high absorption rate of visible light. After combining with Au NFs, the composite CuO NSs@Au NFs produced a strong cathodic photocurrent for the excellent electron conductivity, large specific surface area and Surface Plasmon Resonance effect (SPR) of Au NFs. At the same time, Au NFs provided a binding site for aptamer, which greatly improved the sensitivity of the constructed sensing platform. After the target chloramphenicol (CAP) was specifically captured by the aptamers on the electrode, the formed bioconjugates seriously hindered the transfer of electrons and the absorption of light and caused a reduced photocurrent. For the detection of CAP, this signal off type PEC aptasensor had a linear range of 5 pM-300 nM and a limit of detection of 49.9 fM (S/N = 3) with good stability, selectivity and reproducibility. Meanwhile, the method had satisfactory recovery results in the detection of CAP in real-life samples such as milk, tap water, honey and chloramphenicol eye drops.

DNAzyme amplifaction strategy coupled with peanut-shaped FexOy@MMC@Au and COF@Au synergistic SERS enhancement for ultrasensitive analysis of chloramphenicol

In this study, a target induced DNAzyme amplifaction strategy was developed combining with peanut-shaped FexOy@macro-/mesoporous carbon (MMC)@Au and covalent organic frameworks (COF)@Au to construct surface enhanced Raman spectrum (SERS) aptasensor for ultrasensitive detection of chloramphenicol (CAP). The polydopamine was firstly self-polymerized on the peanut-shaped Fe2O3 as a reductant to generate a uniform assembly of AuNPs, with multiple hotspots, to achieve high reproducibility. After carbonation process, the obtained magnetic peanut-shaped FexOy@MMC@Au could effectively avoid the Raman interference of the SERS substrate. When target CAP was dropped into the aptamer and DNAzyme double chains, CAP could specifically combining with aptamer, releasing DNAzyme chain to cut off hairpin DNA which was already assembled on the FexOy@MMC@Au. At this time, COF@Au@toluidine blue (TB)@S1 can be attract closed to the SERS substrate due to the complementation of S1 with residual hairpin DNA to produce strong Raman signal. Based on this principle, the SERS aptasensor for the detection of CAP possessed a very low limit of detection (LOD) of 7.35 fM was obtained. The results suggested the potential of this SERS aptasensor for sensitive and selective CAP diagnosis and be applied to the clinical and biochemical analysis.

Detection of chloramphenicol in dairy products based on biogas residue biochar based electrochemical sensor

Although N-doped carbon has attracted much attention due to its excellent performance in chloramphenicol (CAP) detection of dairy products, traditional fossil energy sources are costly to develop and environmentally unfriendly. Therefore, in this paper, corn straw biogas residue was selected to prepare biochar, which was an excellent electrode material with simple preparation, high specific surface area, rich pore structure, and good electrical conductivity. A simple, fast and sensitive voltammetric sensor for CAP detection was prepared by using biogas residue biochar and dopamine hydrochloride as raw materials to prepare a biogas residue biochar @polydopamine (BRB@PDA) composite modified glassy carbon electrode and electrodepositing β-cyclodextrin (β-CD) onto the modified electrode. The electrochemical performance of the bare glassy carbon electrode (GCE), β-CD/GCE, BRB@PDA/GCE and β-CD/BRB@PDA/GCE modified electrodes showed that BRB@PDA had excellent electrical conductivity and the deposition of β-CD and BRB@PDA on the electrode surface significantly improved the electron transfer performance. The linear concentration range of the sensor was 5.0 × 10−7-5.0 × 10−4 mol L−1 with a detection limit of 2.0 × 10−8 mol L−1 (S/N = 3), and it showed good reproducibility, satisfactory sensitivity and high specificity. The good accuracy and reliability of β-CD/BRB@PDA/GCE were demonstrated by spiked recovery experiments. Based on the hydrogen bonding between the hydroxyl groups of β-CD/BRB@PDA/GCE, a significant electrochemical signal could be obtained for the detection of chloramphenicol in dairy products. The results reflected the electrochemical performance of the digestate biochar and also indicated that the digestate biochar material had good application prospects in electrochemical detection.

Lateral Flow Immunoassay Based on Quantum-Dot Nanobeads for Detection of Chloramphenicol in Aquatic Products.

Quantum dot nanobeads (QBs) were used as signal source to develop competitive lateral flow immunoassay (LFIA) for the detection of chloramphenicol (CAP). The quantitative detection of CAP was achieved by calculating the total color difference (∆E) values of the test line (T line) using the images of test strips. QB-based LFIA (QBs-LFIA) allowed the effective dynamic linear detection of CAP in the range of 0.1-1.5 ng/mL. The limit of detection (LOD) was 3.0 ng/mL, which was 50 and 667 times lower than those achieved for two different brands of colloidal gold kits. The recoveries of CAP during real-sample detection were 82.82-104.91% at spiked levels of 0.1, 0.7, and 1.5 ng/mL. These results indicate that the developed QBs-LFIA facilitates the sensitive detection of CAP.

Molecularly imprinted polymers-aptamer electrochemical sensor based on dual recognition strategy for high sensitivity detection of chloramphenicol

In this paper, an electrochemical sensor based on a dual recognition strategy of molecularly imprinted polymers (MIPs) and aptamer (Apt) has been designed for the high sensitivity detection of chloramphenicol (CAP). Here, MIPs and Apt have provided dual recognition sites to greatly improve the specific recognition ability of the sensor. Chitosan-multi-walled carbon nanotubes (CS-MWNTs) and AuNPs (gold nanoparticles) have been used for their excellent electrical conductivity. When CAP existed in the detection environment, the imprinted cavities with specific recognition ability bound to CAP through forces such as hydrogen bonds. It hindered the rate of electron transfer and resulted in a decrease in current value. Quantitative detection of CAP could be achieved after analyzing the relationship between the concentration of CAP and the change of current value. After optimizing the experimental parameters, the detection range of the sensor was 10−8 g/L-10−2 g/L with the limit of detection of 3.3 × 10−9 g/L, indicating that the sensor had a high practical application potential.