Ultrasensitive and deployable carbon dots-loaded PVP nanofibrous membranes for enhanced fluorescence-based atrazine detection in water.

Atrazine, a synthetic herbicide from the triazine family, is found to be the most harmful and commonly detected organic pollutant in surface and groundwater. Therefore, there is an increasing demand for sensing platforms that are portable, economical, and capable of rapid detection of trace amounts of atrazine in environmental matrices. So, the present work deals with the facile electrospinning of pure carbon dots (CDs), N-doped CDs (NCDs) and Ag-functionalized CDs (ACDs) embedded in polyvinyl pyrrolidone (PVP)-based electrospun mats (EM), designed for efficient fluorescence-based detection of atrazine in water/aqueous environments. The photophysical (UV-visible and fluorescence spectroscopy), microstructural (XRD, FTIR), morphological (SEM, HRTEM), and thermal (TGA) analysis of the synthesized CDs, as well as the fabricated EM, were thoroughly evaluated. To further understand the sensing performance, interference (in the presence of different analytes) and titration study (at various concentration levels) were performed, which suggested the selective and sensitive behavior of CDs towards atrazine in a concentration-dependent manner. A strong fluorescence-based detection behavior of synthesized CDs was observed with emission peaks centered around ∼440-460 nm. The Stern-Volmer plot suggested the values of detection ∼0.079, ∼ 0.081, and 0.125 μM and reflects that the fabricated system can sense atrazine up to a very low level (∼ 0.017- ∼ 0.0269 μg/mL) for PV-CDs, PV-NCDs and PV-ACDs. To prove the effectiveness of the prepared system, real sample analysis was carried out using different environmental water samples, which suggested ∼ >96% recovery/detection of atrazine. The development of such a nanofibrous atrazine sensing framework may pave the way for a model substitute from the conventionally available approaches to a highly sustainable, environmentally friendly and engineered CDs-based platform for real-time monitoring of triazine-based and/or other similar contaminants in water.