Sensing system for bone health monitoring

Osteoporosis is a disease identified by low bone mass and progressive structural deterioration of bone tissue. Osteoporosis is a serious problem in postmenopausal women and aged populations. There is usually no symptom of osteoporosis until the first bone fracture occurs. Dual-energy X-ray absorptiometry (DEXA) is a gold standard to measure bone mineral density (BMD). The test can diagnose osteoporosis and can conclude if medical treatments are improving bone density. Since changes in bone density are slow, BMD studies are required to be of longer duration, up to 2 years at least, whereas changes in biochemical markers may be evident after only a few weeks. Therefore, detection and quantification of biochemical markers (especially CTX-I) together with the measurement of bone density before deciding whether treatment is required, can help identify bone loss and subsequent response to the treatment. Currently, most of the available techniques to detect and measure bone turnover markers are based on the enzyme-linked immunosorbent assay (ELISA). Although this method is a standard immunoassay technique and has been commercialized, there are serious limitations in using ELISA because it is time-consuming, expensive, requires tedious procedural steps, technical expertise, and a laboratory environment. Therefore, it is very desirable to have an electrochemical biosensing system that is rapid, low-cost, does not require technical expertise and could be applied as a point-of-care tool to establish a realistic measurement profile for osteoporotic patients. It can also be used as a prognostic device at a domestic level that may indicate the early stages of osteoporosis so that the treatment can be started at early stages of the disease before that it could induce irrecoverable loss to the skeletal bones.