Detection of serum calprotectin based on molecularly imprinted photonic hydrogels: A novel approach for IBD diagnosis

Abstract

Inflammatory bowel disease (IBD) affects millions of people worldwide, and current diagnosis relies on a number of complex procedures. The need for sensitive diagnostic tools has focused research on discovering new biomarkers and improving detection methods. Serum calprotectin has recently emerged as a new serological biomarker and shows great potential due to its high specificity. In this work, a label-free biosensor combining molecularly imprinted hydrogels and photonic crystals for the detection of serum calprotectin is presented. The unique inverse opal polymer network with imprinted selective binding sites for serum calprotectin enables a highly sensitive, selective, and fast response. The hierarchical structure combined with the molecular recognition process resulted in swelling of the molecularly imprinted photonic hydrogel (MIPH) when binding the target protein. This effect resulted in a readable shift in the reflection peak to longer wavelengths. The analytical performance of the MIPH was demonstrated by a linear response to clinically relevant calprotectin levels and the achievement of a detection limit of 0.07 ng mL−1 in serum samples. In addition, the sensor proved to be selective for calprotectin when tested for C-reactive protein, another important biomarker of inflammation. In conclusion, this novel approach was successfully used to determine calprotectin concentrations at clinically relevant levels and provides a rapid and effective alternative for IBD diagnosis and medical analysis.