Nanoarchitectonics of nitrogen/selenium functionalized Co-ZIF-9(III) nanorod/nanosheet for nanomolar-level detection of nitrofurantoin antibiotics in environmental and biomedical samples

Designing and developing innovative, cost-effective nanomaterials with outstanding activity and durability remains a significant challenge for next-generation electrochemical sensors. Herein, we developed an energy-efficient approach to synthesize N/Se-functionalized Co-ZIF-9(III) (CZ@N/Se) nanohybrids with a unique nanorod/nanosheet morphology, which serve as a high-performance platform for ultrasensitive nitrofurantoin (NFT) sensing. The unique nanorod/nanosheet morphology of N/Se-doped CZ provides an excellent platform for NFT sensing by enhancing electron-transfer kinetics and generating a high density of active sites through the synergistic interaction between the Co-framework and N/Se dopants. These features facilitate efficient NFT adsorption and catalytic reduction, thereby markedly improving the electrochemical sensitivity and selectivity. With optimized mass loading, the CZ@N/Se nanohybrid exhibits exceptional repeatability and reproducibility in NFT detection, achieving a low detection limit of 1.03 nM and a high sensitivity of 3.783 µA µM⁻¹ cm⁻² as confirmed by multiple electrochemical measurements. Selectivity tests against potential interferents confirmed the sensor's excellent specificity, with negligible interference observed. Besides, the analysis of spiked environmental and biological samples demonstrated accurate detection, validating the sensor reliability and practical applicability for NFT determination in real-world settings.