Tuneable surface enhanced Raman spectroscopy hyphenated to chemically derivatized thin-layer chromatography plates for screening histamine in fish

•A selective SERS-TLC method for reliable determination of histamine was established.•The selectivity-tuning efficacy of NaCl on SERS with derivatized plates was optimized.•The method was both qualitatively and quantitatively validated with fish samples.

Reliable screening of histamine in fish was of urgent importance for food safety. This work presented a highly selective surface enhanced Raman spectroscopy (SERS) method mediated by thin-layer chromatography (TLC), which was tailored for identification and quantitation of histamine. Following separation and derivatization with fluram, plates were assayed with SERS, jointly using silver nanoparticle and NaCl. The latter dramatically suppressed the masking effect caused by excessive fluram throughout the plate, thus offering clear baseline and intensive Raman fingerprints specific to the analyte. Under optimized conditions, the usability of this method was validated by identifying the structural fingerprints of both targeted and unknown compounds in fish samples. Meanwhile, the quantitative results of this method agreed with those by an HPLC method officially suggested by EU for histamine determination. Showing remarkable cost-efficiency and user-friendliness, this facile TLC-SERS method was indeed screening-oriented and may be more attractive to controlling laboratories of limited resource.