Solid-state electrochemiluminescence sensor based on g-C3N4@ZIF-8 for ultrasensitive and specific detection of sulfapyridine

In this study, a solid-state electrochemiluminescence (ECL) sensor was developed for ultrasensitive and specific detection of sulfapyridine (SPY) using graphitic carbon nitride (g-C 3 N 4 ) as a luminescent reagent. The sensor was fabricated by sequentially coating composite material g-C 3 N 4 @ZIF-8 and Nafion onto the electrode surface. The g-C 3 N 4 , synthesized through high-temperature pyrolysis of melamine, generated a sensitive ECL signal in K 2 S 2 O 8 solution. And g-C 3 N 4 served as a carrier for ZIF-8, with the latter acting as a co-reaction promoter within the g-C 3 N 4 -K 2 S 2 O 8 system, leading to a significant enhancement of the ECL signal. Additionally, molecularly imprinted polymers (MIPs) with SPY were introduced to further enhance the performance of the sensor by specifically recognizing SPY. Under optimal conditions, the prepared ECL sensor showed sensitive measurement of SPY in the linear range of 5.0 × 10 −13  ∼ 5.0 × 10 −8 mol/L, with a detection limit (LOD) of 1.67 × 10 −13 (S/N = 3). The developed MIP-ECL sensor demonstrated good stability, high sensitivity, and reliable reproducibility, thus making it suitable for detecting SPY in real samples.