Rapid and sensitive determination of histamine based on a fluorescent aptamer probe with analogue on carbonized polymer dots

Histamine (HA) plays an important role in many pathological processes including asthma, diarrhea, and anaphylactic shock. Therefore, accurate and rapid detecting HA is of great significance. In this work, we report on a novel turn-on fluorescent aptasensor for HA detection based on a competitive combination process performed by both HA-specific and HA-analogs of aptamers. The analogue of HA was environmental-friendly obtained on the polymer chains of carbonized polymer dots (CPDs) without complex functionalization, in which the histidine was used as the polymer precursors for the first time (His-CPDs). After modification with aptamer, the analogue of HA on the His-CPDs would combine with the aptamer, leading to the agglomeration of His-CPDs and the fluorescence quenching. In the presence of HA, the HA would compete with the analogue of HA to react with the aptamer, leading to the dissociation of the agglomerates and the recovery of fluorescence. Under optimized conditions, the proposed fluorescent aptasensor can sensitively detect HA in 7 min ranging from 50 ng/mL to 40 µg/mL with the limit of detection (LOD) of 30 ng/mL. More importantly, this proposed fluorescent aptasensor can sensitively detect histamine in human serum and real sardine samples without complex pre-processing, showing great potential in the medical diagnosis of histamine intoxication and anaphylactic shock.