Pharmaceutical and food pollutants have threatened global health. Pharmacotherapy has left a positive impression in the field of health and life of people and animals. However, the many unresolved problems brought along with residues of pharmaceuticals in the environmental and food. Consumption of the world's freshwater resources, toxic chemicals, air pollution, plastic waste directly affects water and soil resources. Pesticides have a wide role in pollutants. Therefore, the determination of pesticides is significant to eliminate their negative effects on living things. Nowadays, there are many analytical methods available. However, new analysis methods are still being researched due to certain limitations of traditional methods. Electrochemical sensors have drawn attention because of their superior properties, such as short analysis time, affordability, high sensitivity, and selectivity. The development of new analytical strategies for assessing risks from pharmaceutical to food pollutants in water and soil sources is important for the measurement of different pollutants. Moreover, the 2D-carbon nanomaterials used in the development of electrochemical sensors are widely utilized to enlarge the surface area, increase porosity, and make easy immobilization. Graphene (graphene derivations) and carbon nanotubes integrated nanosensors are widely used for the determination of pesticides. 2D-carbon nanomaterials can be tailored according to the purpose of the study. The characterization and synthesis methods of 2D-carbon nanomaterials are widely explained. Furthermore, enzyme nanobiosensors, especially Acetylcholinesterase (AChE), are widely used to determine pesticides. The three main topics are focused on in this review: 2D-carbon nanomaterials, pesticides that threaten life, and the application of 2D-carbon nanomaterials-based electrochemical sensors. The various developed 2D-carbon nanomaterials-based electrochemical sensors were applied in pharmaceutical forms, fruits, tap/lake water, beverages, and soils sources. This work aims to indicate the recently published paper related to pesticide analysis and highlight the importance of 2D-nanomaterials on sensors.

Organophosphate (OP) pesticides remain a worldwide health concern due to their acute or chronic poisoning and widespread use in agriculture around the world. There is a need for robust and field-deployable tools for onsite detection of OP pesticides in food and water. Herein, we present an integrated smartphone/resistive biosensor for simple, rapid, reagentless, and sensitive monitoring of OP pesticides in food and environmental water. The biosensor leverages the hydrolytic activity of acetylcholinesterase (AChE) to its substrate, acetylcholine (ACh), and unique transport properties of polyaniline nanofibers (PAnNFs) of chitosan/AChE/PAnNF/carbon nanotube (CNT) nanocomposite film on a gold interdigitated electrode. The principle of the sensor relies on OP inhibiting AChE, thus, reducing the rate of ACh hydrolysis and consequently decreasing the rate of protons doping the PAnNFs. Such resulted decrease in conductance of PAnNF can be used to quantify OP pesticides in a sample. A mobile app for the biosensor was developed for analyzing measurement data and displaying and sharing testing results. Under optimal conditions, the biosensor demonstrated a wide linear range (1 ppt–100 ppb) with a low detection limit (0.304 ppt) and high reproducibility (RSD <5%) for Paraoxon-Methyl (PM), a model analyte. Furthermore, the biosensor was successfully applied for analyzing PM spiked food/water samples with an average recovery rate of 98.3% and provided comparable results with liquid chromatography-mass spectrometry. As such, the nanosensing platform provides a promising tool for onsite rapid and sensitive detection of OP pesticides in food and environmental water.

Evaluation of acetylcholinesterase (AChE) activity and determination of organophosphorus pesticides (OPs) are of great importance for the clinical diagnosis of several serious diseases correlated with their variations in human blood serum. In this study, a highly selective and sensitive ratiometric fluorescent probe was innovatively fabricated for the evaluation of AChE activity and the determination of OPs in tap water and food on the basis of the inner filter effect (IFE) between nitrogen-doped carbon dots (N-CDs) and 2,3-diaminophenazine (DAP). N-CDs were synthesized via a one-pot hydrothermal method by using pancreatin and 1,2-ethanediamine as precursors. N-CDs showed excellent fluorescence properties and negligible cytotoxicity on human cervical carcinoma HeLa cells and human embryonic kidney 293T cells, suggesting their further biological applications. Upon the addition of AChE and choline oxidase, acetylcholine was catalyzed to produce choline that was further oxidized to produce H₂O₂. In the presence of horseradish peroxidase, o-phenylenediamine reacted with H₂O₂ to produce fluorescent DAP. Therefore, a ratiometric fluorescent probing platform existed via IFE between N-CDs with a fluorescence signal at 450 nm and DAP with a fluorescence signal at 574 nm. OPs irreversibly impeded the catalytic activity of AChE, finally leading to the decrease of DAP amount and the variation of ratiometric fluorescent signal. Under optimal conditions, such a fluorescent probe showed relatively low detection limits of 0.38 U/L for AChE, 3.2 ppb for dichlorvos, and 13 ppb for methyl-parathion. Practical application of this ratiometric fluorescent probe to detect OPs was further verified in tap water and food samples with satisfying results that were highly consisted with the results obtained by GC–MS.