A Portable Microfluidic Photometric Detection Method Based on Enzyme Linked Immunoscatter Enhancement

Abstract

Currently, the combination of smart phones and microfluidic chips is a commonly used device for point-of-care testing (POCT) detection. Enzyme linked immunosorbent assay (ELISA), as an effective method for the detection of specific proteins in diseases, has not been widely used in combination with smart phones and microfluidic chips, mainly because the detection accuracy of smart phone cameras is difficult to directly replace high-precision spectral devices. Therefore, this paper proposes a microfluidic photometric detection method based on ELISA scattering enhancement. Firstly, the scattering characteristics of IMB were mined and the optimum absorbance error compensation parameters were analyzed. Secondly, the absorbance error compensation model based on scattering enhancement characteristics is established to improve the image acquisition accuracy of smart phones. Finally, a microfluidic photometric detection chip was developed and a detection platform was established to design POCT detection App for smart phones. The optimal compensation parameters of IMB were obtained based on simulated samples, and the linearity of absorbance and concentration increased by 22.6% after compensation. In the IL-6 sample experiment, the detection results of the platform in this paper had a good linear correlation with IL-6 sample concentration, and the linear correlation coefficient was above 0.95459. At the same time, the detection limit and accuracy meet the detection requirements. Therefore, with the participation of smart phones and microfluidic chips, traditional ELISA solves problems such as difficult portability and complex operation in daily detection, laying a foundation for the promotion and application of ELISA based POCT platform in the future.

Keywords: POCT, microfluidic technology, ELISA, IMB, Light scattering enhancement