Development of IoT-based impedometric biosensor for point-of-care monitoring of bone loss

Early detection of disease is essential for an efficient treatment. Bone loss can be detected and monitored by regular measurement of serum or urine C-terminal telopeptide of type 1 collagen (CTx-1). Therefore, rapid, portable and low-cost point-of-care devices are highly desirable. In this paper, we have reported an IoT-based selective, sensitive, quick and inexpensive device for the quantification of CTx-1 levels in serum. A capacitive interdigital sensor was coated with artificial antibodies, prepared by molecular imprinting technology. Electrochemical impedance spectroscopy was used to evaluate the resistive and capacitive properties of the sample solutions. A microcontroller-based system was developed for the measurement of the level of CTx-1 in serum and for data transmission to an Internet of Things (IoT)-based cloud server. The data can be provided to the medical practitioner and a detailed investigation can start for early detection and treatment. The developed sensing system responded linearly in a range of 0.1 ppb to 2.5 ppb, which covers the normal reference range of CTx-1 in serum, with a limit of detection (LOD) of 0.09 ppb. The results demonstrated that the proposed portable biosensing system could provide a rapid, simple and selective approach for CTx-1 measurement in serum. Sheep serum samples were tested using the proposed system and the validation of the results was done using an enzyme-linked immunosorbent assay (ELISA) kit.