Rationally designed smartphone-assisted dual-mode sensing platform based on B, N-doped carbon dots for fluorescent and colorimetric detection of propyl gallate

The development of rapid and sensitive detection methods for propyl Gallate (PG) is crucial due to its significant threats to human health and the environmental safety. Here, B, N co-doped carbon dots (BN-CDs) were designed by employing 5-boronoisophthal and o -phenylenediamine as precursors to enable fluorimetric and colorimetric dual-mode detecting of PG. Specifically, the presence of PG could result in a decrease in fluorescence intensity, while simultaneously leading to the formation of a distinctive tawny complex that exhibited a pronounced colorimetric response. The fluorimetric and colorimetric mode demonstrated dependable selectivity and exceptional sensitivity, with detection limits of 0.12 μg/mL and 0.27 μg/mL, respectively. The fluorescence sensing mechanism was confirmed to be attributed to the static quenching effect (SQE) through both experimental results and density functional theory (DFT) analysis, indicating that the "ON-OFF" progress could be ascribed to the formation of a non-luminescent substance. Additionally, the application of actual samples detection demonstrated outstanding self-calibration capabilities and achieved satisfactory recovery rats ranging from 94.0 % to 112.0 %. Furthermore, the smartphone-assisted sensing system exhibited the capability to conveniently and visually assess PG levels by accurately distinguish subtle variations in color. The study presents an effective dual-mode sensing approach for rapid and accurate detection of PG, which offers significant benefits in reducing the probability of PG exposure.