Microfluidic paper-based chip platform for formaldehyde concentration detection

An integrated platform consisting of a microfluidic paper-based chip and a mini-box detection system is proposed for the concentration detection of formaldehyde. In the proposed approach, the reaction region of the paper-based chip is implanted with Acetoacetanilide reagent, and the formaldehyde concentration is deduced from the UV light-induced fluorescence intensity of the formaldehyde-Acetoacetanilide complex (dihydropyridine) produced in a Hantzsch reaction process at room temperature for 2 min. The experimental results obtained using control samples with formaldehyde concentrations ranging from 0 to 8 ppm show that the formaldehyde concentration (Y) and fluorescence intensity (X) are related as Y = 0.0039 e(0.058X). Moreover, the correlation coefficient (R-2) is equal to 0.9987. The real-world applicability of the proposed paper-based platform is demonstrated by measuring the formaldehyde concentration in eleven commercial food samples. It is found that the measurement results deviate from those obtained using a standard bench top method by no more than 4.7%. Overall, the results presented in this study show that the proposed system provides a rapid and reliable technique for formaldehyde concentration detection.