Quantitative Detection of Thyroid‐Stimulating Hormone in Patient Samples with a Nanomechanical Single‐Antibody Spectro‐Immunoassay

Abstract Functional disorders of the thyroid remain a global challenge and have profound impacts on human health. Serving as the barometer for thyroid function, thyroid‐stimulating hormone (TSH) is considered the single most useful test of thyroid function. However, the prevailing TSH immunoassays rely on two types of antibodies in a sandwich format. The requirement of repeated incubation and washing further complicates the issue, making it unable to meet the requirements of the shifting public health landscape that demands rapid, sensitive, and low‐cost TSH tests. Herein, a systematic study is performed to investigate the clinical translational potential of a single antibody‐based biosensing platform for the TSH test. The biosensing platform leverages Raman spectral variations induced by the interaction between a TSH antigen and a Raman molecule‐conjugated TSH antibody. In conjunction with machine learning, it allows TSH concentrations in various patient samples to be predicted with high accuracy and precision, which is robust against substrate‐to‐substrate, intra‐substrate, and day‐to‐day variations. It is envisioned that the simplicity and generalizability of this single‐antibody immunoassay coupled with the demonstrated performance in patient samples pave the way for it to be widely applied in clinical settings for low‐cost detection of hormones, other molecular biomarkers, DNA, RNA, and pathogens.