Controllable Enhanced Ru(bpy)32+ Electrochemiluminescence Detection Systems Based on Eu@MOF253@AuNPs/GCE for the Sensitive Detection of Carbaryl in Food

Self-luminescent dual-ligand metal-organic framework based electrochemiluminescence probes for organophosphorus pesticides determination

In this study, a signal amplification strategy was developed, which tris (2, 2'-bipyridyl) ruthenium (II) (Ru(bpy)32+) was incorporated as a guest molecule into the preparation system of lanthanide-based metal-organic framework (MOF). This strategy relied on strong electrostatic interactions and coordination competition to influence the growth process of the MOF, resulting in the firm immobilization of Ru(bpy)32+ within the MOF structure. The spatial confinement effect of the MOF effectively improved the efficiency of electron transfer in the electrochemiluminescence (ECL) reaction. The constructed ECL aptasensor using this MOF exhibited excellent performance, with limits of detection (LODs) for four organophosphorus pesticides (OPs), phorate, profenofos, isocarbophos and omethoate, as low as 0.0482 ng/mL, 0.0093 ng/mL, 0.0085 ng/mL, and 0.0893 ng/mL, respectively. This work has paved the way for a clever strategy of immobilizing Ru(bpy)32+ molecules and amplifying signals, expanding the application of dual-ligand MOF, which provides valuable insights for future biosensor design.

MOF@Ag/AAB/Au@Ag composite matrix full-dimensional divergence effect-based SERS paper sensor for rapid carbaryl quantification

Carbaryl is a broad-spectrum carbamate fungicide that may pose a threat to ecosystems and human health. To prevent and control the harm caused by excessive application of carbaryl, a full-dimensional divergence effect SERS sensor has been constructed. Biodegradable paper chips were used as sensor substrates. ZIF-8 with structural flexibility was grown in situ on carbon paper. A rough silver layer with surface like metal etching was clad outside the ZIF-8. Artificial antibody (AAB) with accurate grasping ability was polymerized on the surface of ZIF-8@Ag paper substrate. Au@Ag CSNPs were decorated on the AAB to provide abundant "hot spots". Every functional material layer works together to form a gap and tip region with superior plasmon resonance. The proposed SERS sensor realizes the rapid and accurate on-site screening and localization of carbaryl in food with good correlation responded in the range of 0.01-20 μg·mL-1 and a low detection limit of 5.72 × 10-‍3‌ μg·mL-1.

Regenerable AgNPs-CdSNWs/Nanofilm as SERS substrates for sensitive detection of carbamate pesticides

The accurate detection of carbamate pesticides popularly employed in agricultural products is critical for reducing the threat of resultant residues to human health. In this work, a regenerable nanofilm used for SERS substrate was constructed by interfacially confined self-assembly incorporating CdS nanowires (CdSNWs) and Ag nanoparticles (AgNPs). The constructed AgNPs-CdSNWs/Nanofilm could significantly enhance the Raman signals of three carbamate pesticides (metolcarb, carbaryl and aldicarb-sulfone). A broad detection linear ranged 0.001-100 mg/L was achieved. The detection limits (LOD) of metolcarb, carbaryl and aldicarb-sulfone reached 0.00081 mg/L, 0.00081 mg/L and 0.00072 mg/L with coefficients of determination of (R2) of 0.992, 0.991 and 0.992, percent recovery ranged 86.5-104.9 %，88.2-105.1 % and 87.0-104.5 %, respectively, and relative standard deviation (RSD) values were all less than 4.0 %. Results showed that the user-friendly reproducible nanofilm could be employed as simple-to-establish SERS platform for rapid detection of carbamate pesticides in food.

Recent advance for enantiorecognition of chiral drugs sensing: Electrochemical, electrochemiluminescent and photoelectrochemical application

Chiral isomers show different behaviours and properties in physiological activities. It is of great significance to find productive approach to realize the recognition of enantiomers, which is a key issue in biochemical and pharmaceutical fields. Nowadays, chiral identification can be successfully achieved according to the discrepancies of special signals correlated with different enantiomers of multiple electrode structures. Electrochemical technologies have attracted wide interest in enantioselective analysis because of its unique merits, such as the economic and miniaturized instruments, simplified and environmental-friendly sample preparations. This review summarizes the development trends of electrochemical sensing in the enantiospecific analysis of chiral drugs, expounds the enantiospecific recognition mechanism between chiral selector and target enantiomers based on general electrochemical, electrochemiluminescent and photoelectrochemical sensors, respectively. In addition, this review attempts to predict the future application of electrochemical, electrochemiluminescent and photoelectrochemical-based technologies in the enantioselective recognition and detection.

Eu3+-Doped Anionic Zinc-Based Organic Framework Ratio Fluorescence Sensing Platform: Supersensitive Visual Identification of Prescription Drugs

Advanced techniques for both environmental and biological prescription drug monitoring are of ongoing interest. In this work, a fluorescent sensor based on an Eu3+-doped anionic zinc-based metal-organic framework (Eu3+@Zn-MOF) was constructed for rapid visual analysis of the prescription drug molecule demecycline (DEM), achieving both high sensitivity and selectivity. The ligand 2-amino-[1,1'-biphenyl]-4,4'-dicarboxylic acid (bpdc-NH2) not only provides stable cyan fluorescence (467 nm) for the framework through intramolecular charge transfer of bpdc-NH2 infinitesimal disturbanced by Zn2+ but also chelates Eu3+, resulting in red (617 nm) fluorescence. Through the synergy of photoinduced electron transfer and the antenna effect, a bidirectional response to DEM is achieved, enabling concentration quantification. The Eu3+@Zn-MOF platform exhibits a wide linear range (0.25-2.5 μM) to DEM and a detection limit (LOD) of 10.9 nM. Further, we integrated the DEM sensing platform into a paper-based system and utilized a smartphone for the visual detection of DEM in water samples and milk products, demonstrating the potential for large-scale, low-cost utilization of the technology.

Ultrasensitive Electrochemiluminescence Sensor Utilizing Aggregation-Induced Emission Active Probe for Accurate Arsenite Quantification in Rice Grains

Arsenic (As) constitutes a substantial threat to global ecosystems and public health. An accurate quantification of inorganic arsenite (As(III)) in rice grains is crucial for ensuring food safety and human well-being. Herein, we constructed an electrochemiluminescence (ECL) biosensor utilizing aggregation-induced emission (AIE) active Pdots for the sensitive detection of As(III) in rice. We synthesized tetraphenylethylene-based AIE-active Pdots, exhibiting stable and highly efficient ECL emission in their aggregated states. Owing to the overlap of spectra, we employed an electrochemiluminescence resonance energy transfer (ECL-RET) system, with the Pdots as the donor and black hole quencher (BHQ) as the acceptor. Upon the introduction of As(III), the conformational changes of As(III)-specific aptamer could trigger the detachment of BHQ-labeled DNA aptamer from the electrode surface, leading to the recovery of the ECL signal. The target-induced "signal-on" bioassay enabled the sensitive and specific detection of As(III) with a linear range of 10 pM to 500 nM, with an ultralow limit of detection (LOD) of 5.8 pM/0.4 ppt. These values significantly surpass those of existing sensors designed for As(III) quantification in rice. Furthermore, by employing amylase hydrolysis for efficient extraction, we successfully applied our sensor to measure As(III) in actual rice samples sourced from diverse regions of China. The results obtained using our sensor were in close agreement with those derived from the reference method of HPLC-ICP-MS. This study not only presents a sensitive and reliable method for detecting arsenite but also underscores its potential applications in enhancing food safety, agriculture practices, and environmental monitoring.

Emerging Insights into the Use of Advanced Nanomaterials for the Electrochemiluminescence Biosensor of Pesticide Residues in Plant-Derived Foodstuff

Pesticides have an important role in rising the overall productivity and yield of agricultural foods by eliminating and controlling insects, pests, fungi, and various plant-related illnesses. However, the overuse of pesticides has caused pesticide pollution of water bodies and food products, along with disruption of environmental and ecological systems. In this regard, developing low-cost, simple, and rapid-detecting approaches for the accurate, rapid, efficient, and on-site screening of pesticide residues is an ongoing challenge. Electrochemiluminescence (ECL) possesses the benefits of great sensitivity, the capability to resolve several analytes using different emission wavelengths or redox potentials, and excellent control over the light radiation in time and space, making it a powerful strategy for sensing various pesticides. Cost-effective and simple ECL systems allow sensitive, selective, and accurate quantification of pesticides in agricultural fields. Particularly, the development and progress of nanomaterials, aptamer/antibody recognition, electric/photo-sensing, and their integration with electrochemiluminescence sensing technology has presented the hopeful potential in reporting the residual amounts of pesticides. Current trends in the application of nanoparticles are debated, with an emphasis on sensor substrates using aptamer, antibodies, enzymes, and molecularly imprinted polymers (MIPs). Different strategies are enclosed in labeled and label-free sensing along with luminescence determination approaches (signal-off, signal-on, and signal-switch modes). Finally, the recent challenges and upcoming prospects in this ground are also put forward.