Development of a smartphone-integrated microfluidic paper-based optosensing platform coupled with molecular imprinting technique for in-situ determination of histamine in canned tuna.

We reported the development of a smartphone-integrated microfluidic paper-based optosensing platform for in-situ detection and quantification of histamine in canned tuna. Molecularly imprinted polymers were synthesized via precipitation polymerization and utilized as dispersive solid phase extraction sorbent to selectively extract histamine from canned tuna. Carbon quantum dots functioning as a fluorescent probe were synthesized and introduced onto the microzones of the microfluidic paper device. This facilitated a noticeable fluorescence color change from dark red to vivid blue upon the addition of histamine. The change in fluorescence on the paper device was converted into specific RGB values using a portable UV light box combined with a smartphone. This assay achieved the limit of detection of 14.04 mg/kg with the linear range from 20 to 100 mg/kg of histamine in canned tuna. The entire molecular imprinting-microfluidic optosensing test could be completed in 45 min including sample preparation.