Fluorescence enhancing and quenching signal based on new approach for selective detection of multiple organochlorine pesticides using blue emissive-carbon dot

Abstract

Measuring the concentration of organochlorine pesticides (OCPs) in agriculture has engaged significant awareness for healthcare investigation since OCPs are harmful to many physiological processes. Excessive usage of these compounds can result in major contamination of the environment and food supply chains. As a result, more accurate and rapid ways to detect pesticide residues in food are required. In this work, we have portrayed the surface-engineered fluorescent blue emissive-carbon dot (B-CD) with a high quantum yield (49.3 %) via the hydrothermal method for fluorescent sensing of OCPs on real samples. The amine group functionalities of carbon dots have supported the direct coordination with -Cl and -OH groups of HEP, ENS, CDF and 2,4-DPAC for the sensitive detection of OCPs, by switching in the fluorescent intensity of B-CD. The functional group of OCPs exhibits a variety of binding interactions with B-CD to contribute a complex formation, which leads to static quenching via an insubstantial restricted electron transfer process. The synthesized carbon dots exhibit individuality in binding nature towards different OCPs. Fluorescence studies help to distinguish the target OCPs and their low detection limits (LODs) were 0.002, 0.099, 0.16 and 0.082 μM for Heptachlor (HEP - turn "on"), Endosulfan (ENS), Chlordimeform (CDF) and 2,4-dichlorophenoxyacetic acid (2,4-DPAC - turn "off") OCPs respectively. The real water samples and agriculture food samples were effectively investigated and the OCP toxicity was noted. Thus, the design of the fluorescence sensor is established as an easy and proficient sensing method for detecting OCPs.

Keywords: B-CD; Binding affinity; Biodegradable; Fluorescence quenching; OCPs; Sensor.