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

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 λ_ex 365 nm and λ_em 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.