Electrochemical simultaneous sensor based on CaZrO3@attapulgite hybrid nanocomposite for environmental monitoring of metronidazole and nitenpyram pestanal.

In this study, an environmentally friendly, highly selective, and sensitive electrochemical sensor was developed for the simultaneous determination of antibiotic metronidazole (MTR) and pesticide nitenpyram (NTP) using a calcium zirconate@attapulgite-modified glassy carbon electrode (CaZrO3@ATP/GCE). The hybrid nanocomposite was synthesized by a hydrothermal and simple sonochemical route that enabled the uniform deposition of CaZrO3 nanoparticles on the fibrous attapulgite (ATP) porous structures to form a highly conductive and electroactive nanocomposite. The hybrid nanocomposite was suggesting the CaZrO3 and ATP network exhibit synergistic and highly surface catalytic activity. Using differential pulse voltammetry (DPV), the sensor exhibited high selectivity and strong sensitivity (MTR: 0.7398 μA μM-1 cm-1 & NTP: 0.4869 μA μM-1 cm-1) with detection ranges of MTR: 0.1 to 1525.1 μM (detection limit of 0.033 μM) and NTP: 0.2-945 μM (detection limit of 0.065 μM). The fabricated electrodes were interference-free during simultaneous detection of relevant compounds, high reproducibility and stability, suggesting those systems were ready for practical, portable applications in environmental monitoring. Real-sample validation of sediment water, pond water, human serum, and urine are reported, with exceptional recovery values (∼96.7-100.8%) and the HPLC method also showed satisfactory recoveries (98.9-101%) representing sensor reliability vis-a-vis complex matrices. This work represents the first demonstration of a CaZrO3@ATP hybrid nanocomposite as a platform for the provision of electrochemical sensing, premium, inexpensive, and scalable strategies for multi-residue ranging from environmental immunology to human biofluids, bridging fundamental gaps in the environmental-health surveillance and food safety nexus.