A comprehensive review of C-reactive protein testing methods: from current status to future prospects

C-reactive protein (CRP), a sensitive inflammatory biomarker, is predominantly synthesised by the liver. Its concentration rises rapidly in response to infection, inflammation, or tissue injury. Persistent or excessive elevation of CRP is associated with serious health risks, including cardiovascular disease and acute or chronic kidney injury. Owing to its high sensitivity to inflammation, infection, and cardiovascular risk, CRP is widely regarded as a key biomarker for assessing these conditions. Conventional detection methods, such as immunoturbidimetry (ITM), enzyme-linked immunosorbent assay (ELISA), and lateral flow immunoassay (LFIA), are often constrained by high cost, complex operation, and cumbersome processes. Recent advances integrating biosensing, microfluidics, and nanomaterials have led to the development of multi-dimensional, synergistic detection platforms, substantially enhancing CRP detection performance. This review comprehensively summarises recent progress in CRP detection technologies, focusing on three major approaches: immunoassays, electrochemical detection, and optical sensing. The core principles and performance optimisation strategies of these techniques are elucidated, with particular attention given to emerging sweat-based detection methods. An in-depth analysis of their sensor design, analytical challenges, and point-of-care application potential is provided. Furthermore, the review systematically outlines future prospects for point-of-care testing (POCT) of CRP using non-invasive biofluids like sweat. This review aims to systematically summarise detection methods for CRP, thereby offering diagnostic researchers a reference guide that integrates cutting-edge insights with practical value.