Thermally Regulated HOF-101/MXene-Driven PEC/ECL Dual-Mode Molecularly Imprinted Sensor for Sensitive Detection of Nitrofurazone

Abstract The great promise of hydrogen-bonded organic frameworks (HOFs) in photoelectrochemical (PEC) and electrochemiluminescence (ECL) sensing is restricted by poor stability and low sensitivity. In this study, thermal regulation is employed to adjust the molecular packing and framework connectivity of HOF-101. The annealed HOF-101 with a fundamental periodic framework can provide a pronounced photocurrent response. Consequently, a mode-adapted HOF-101/MXene is employed in the dual-mode PEC/ECL molecularly imprinted sensor, enabling sensitive and reliable detection of nitrofurazone (NFZ), a nitrofuran antibiotic of significant regulatory concern. MXene functions either as an efficient charge-transport support to suppress photogenerated charge recombination and accelerate the interfacial reaction, or as an efficient coreactant accelerator to promote the redox kinetics of HOF-101 to boost its ECL emission. Thanks to stable and reliable dual-mode readout, the proposed sensor has a wide linear range of 1.0 × 10−1−1.0 × 105 ng mL−1 in PEC mode and 1.0 × 100−1.0 × 105 ng mL−1 in ECL mode, with a detection limit of 3.7 × 10−2 ng mL−1 and 2.3 × 10−2 ng mL−1, respectively. The sensor demonstrates good selectivity and satisfactory recoveries in river water samples. This work presents a potential platform for determining NFZs in environmental water monitoring and offers new insights into the thermally induced structural regulation of HOFs-based heterostructures for high-performance PEC/ECL sensing.