Label-Free Evaluation of Human Serum Albumin Using Ordered Porous Layer Optical Interferometry

This is the authors' abstract. We don't add key points for this paper.

The determination of human serum albumin (HSA) is of great significance for the noninvasive diagnosis and treatment of modern diseases. Label-free immunoassay has been regarded as one of the most prominent techniques for HSA detection because of its reliability and sensitivity. In this work, an optical label-free biosensing method based on ordered porous polystyrene inverse opal (PS-IO) substrate was developed. Based on the methodology of inhibitory immunoassay, human serum albumin (HSA) was immobilized on the PS substrate with sufficient density, enabling one-step detection, while the interconnected inverse opal substrate enhances the mass transfer efficiency of the sensing unit. HSA level can be determined without either the label of protein molecules or sensor signal amplification, which simplifies the operation procedure and improves the detection efficiency. The linear range of the developed sensing system is 0.05–50 μg/mL, with a limit of quantitation of 50 ng/mL. At the same time, the sensor has strong selectivity and specificity, resists environmental molecular interference, and maintains stable sensing performance during long-term storage and recycling. This study provides valuable insights for the development of new clinical measurement devices.