A surface-enhanced Raman scattering-based competitive lateral flow assay for on-orbit rapid detection of bone loss biomarker CTX I

The complexity of space environment will lead to a series of health problems, especially the bone loss caused by weightlessness is one of the key medical problems limiting long-term manned space flight. However, the size and energy constraints of the aircraft make conventional bone loss detection methods impractical. Hence, it is necessary to establish on-orbit bone loss detection methods to ensure the health of astronauts. As one of NASA's recommended methods, the lateral flow assay (LFA) would be an ideal tool to solve this problem. Herein, a surface-enhanced Raman based molecular probe was designed and integrated with LFA to detect carboxy-terminal cross-linked telopeptides of type I collagen (CTX I) with high sensitivity and specificity, and the limit of detection was 232 pg/mL. This method was not interference by the serum matrix or other targets, and the storage life of LFA was up to 6 months at 4 °C. Compared with the method previously reported, SERS-based LFA was an ideal detection method with simple operation, convenient and time saving. It is also expected to be chosen as a potential analytical tool to detect bone loss for long-term on-orbit, and guarantee the health of astronauts.