CRISPR-Cas-Based Platform for Single-Step Quantification of Monoclonal Antibodies at Point-of-Care

We report a streamlined, cost-effective point-of-care platform for the quantitative detection of monoclonal antibodies for therapeutic drug monitoring, addressing the limitations of bulky, complex, and expensive instrumentation required for standard analytical techniques. In contrast to conventional immunoassays that rely on primary/secondary antibodies for quantification, our method leverages a DNA circuit for the recognition of the target monoclonal antibody coupled with CRISPR-Cas12a signal amplification. This assay is integrated into a microfluidic chip that enables a single-step workflow, eliminating the multiple incubations and reagent addition steps typical of laboratory methods. The platform demonstrates quantitative detection of a model anti-hemagglutinin antibody within a 60-min sample-to-answer timeframe, in the nanomolar range, with a chip manufacturing cost below 1€ and reagent stability confirmed at -20 °C for over one month. This proof-of-concept illustrates the potential of simplified CRISPR-based assays for decentralized rapid protein quantification in clinical settings.