An in-situ photoderivative fluorescence enhancement method without chromatographic separation for Aflatoxin B1 (AFB1) detection.

Aflatoxin B1 (AFB1), a potent carcinogenic mycotoxin, poses critical health risks to both animals and humans. Thus, rapid and highly sensitive detection of AFB1 is crucial for ensuring food safety. However, current AFB1 detection methods face a trade-off between laboratory-level sensitivity and on-site immediacy. Instead of relying on absolute fluorescence intensity, this study exploits the UV-triggered addition at the terminal furan double bond of AFB1, which yields a large fluorescence enhancement (ΔF), thereby proposing a novel quantification strategy centered on this photo-induced signal increment. By optimizing the solvent environment for photochemical derivatization (PD), we obtained the maximum ΔF at methanol-water (30:70, v/v) with λex 365 nm and λem 430 nm. Based on these findings, a miniaturized in-situ PD fluorescence device (85 mm × 65 mm × 60 mm) equipped with a high-background shutter for precise ΔF onset measurement was fabricated. The method exhibited a linear response over 0.05-200 µg L-1 with a limit of detection at 0.024 µg L-1 (S/N = 3) and a rapid response time of less than 2 min, enabling chromatography-free, selective, and sensitive quantification of AFB1 in complex matrices. Actual spiked samples showed 93.68%- 116.30% recovery. And the AFB1-positive samples in platyclade semen agree well with HPLC-PD-FLD (relative error: 3.46%). The proposed ΔF method combines high sensitivity, good anti-interference capability, and portability, offering a reliable new tool for on-site screening of AFB1.