Intelligent Colorimetric Determination of Biomercaptan in Urine

Mercaptan is involved in many physiological and pathological processes in human body, reflecting the homeostasis of internal circulation. If the content of biomercaptan in the urine is more than 1.0 mmol/L, it indicates physical abnormalities. The quantitative determination of biomercaptan is helpful for daily health evaluation and clinical diagnosis, but the current methods commonly used are instrumental analysis methods. Therefore, it is urgent to build a home environment applicable, convenient, visual and intelligent detection method. The blue complex of Zincon-Zn2+ as a new colorimetric reagent for biomercaptan determination was designed in this work. When the biomercaptan existed in sample, Zn2+ could be released from Zincon-Zn2+ and combined with the biolmercaptan via sulfydryl for stronger coordination ability, and then Zincon with purplish red was kept in the colorimetric sensor. Electrospinning was used to ensure the reproducibility of the colorimetric sensor by establishing a protection mechanism of chromogenic agents based on polyacrylonitrile, thin-layer chromatography silica gel and polyvinylpyrrolidone. The selectivity of the sensor was revealed by the anti-interference experiment of 19 kinds of common amino acids. The spectral interference on the colorimetric determination was overcome by the combination of colorimetric development and artificial intelligence model. Convolutional neural networks had good predictive accuracy and could be integrated into smart phone APP, which could be developed into a full analysis system for biomercaptan in urine, with the virtue of rapid sampling, data processing and transmission, real-time and visual detection. This new system could be adopted for non-invasive prediction of cervical cancer and urinary diseases with low cost, fast detection, easy operation, good accuracy, high accuracy (98%) and low detection limit (0.01 mmol/L).