Development of a smart sensing system for early detection of osteoporosis

Theoretical thesis.Bibliography: pages 119-143.1. Introduction -- 2. Literature review -- 3. Planar interdigital sensors and electrochemical impedence spectroscopy -- 4. Antigen-antibody-based sensor for CTx-I detection -- 5. MIP-based sensor for CTx-1 detection -- 6. IoT-enabled microcontroller-based system -- 7. Conclusion and future work.Early detection of any 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-I). Therefore, rapid, sensitive, accurate, portable and low-cost point-of-care devices are highly desirable. In this research, we have proposed a selective, sensitive, quick and inexpensive Internet of Things (IoT)-based device for the quantification of CTx-I levels in serum. A capacitive interdigital sensor with multi-sensing electrode configuration was employed to perform the experiments. Initially, natural antibodies were used to introduce selectivity for the target molecule. In spite of the high selectivity and sensitivity of the proposed system, there were some limitations in using natural antibodies. Natural antibodies are very expensive, sensitive to harsh environmental conditions and have limited stability. In order to overcome these limitations, the 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-I in serum and for data transmission to an 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-I 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 CTxI 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.1 online resource (xx, 143 pages : illustrations

Smart Sensing System for Early Detection of Bone Loss: Current Status and Future Possibilities

Bone loss and osteoporosis is a serious health problem worldwide. The impact of osteoporosis is far greater than many other serious health problems, such as breast and prostate cancers. Statistically, one in three women and one in five men over 50 years of age will experience osteoporotic fractures in their life. In this paper, the design and development of a portable IoT-based sensing system for early detection of bone loss have been presented. The CTx-I biomarker was measured in serum samples as a marker of bone resorption. A planar interdigital sensor was used to evaluate the changes in impedance by any variation in the level of CTx-I. Artificial antibodies were used to introduce selectivity to the sensor for CTx-I molecule. Artificial antibodies for CTx-I molecules were created using molecular imprinted polymer (MIP) technique in order to increase the stability of the system and reduce the production cost and complexity of the assay procedure. Real serum samples collected from sheep blood were tested and the result validation was done by using an ELISA kit. The PoC device was able to detect CTx-I concentration as low as 0.09 ng/mL. It exhibited an excellent linear behavior in the range of 0.1–2.5 ng/mL, which covers the normal reference ranges required for bone loss detection. Future possibilities to develop a smart toilet for simultaneous measurement of different bone turnover biomarkers was also discussed

Recent progress in 3D printed mold-based sensors

The paper presents a review of some of the significant research done on 3D printed mold-based sensors performed in recent times. The utilization of the master molds to fabricate the different parts of the sensing prototypes have been followed for quite some time due to certain distinct advantages. Some of them are easy template preparation, easy customization of the developed products, quick fabrication, and minimized electronic waste. The paper explains the different kinds of sensors and actuators that have been developed using this technique, based on their varied structural dimensions, processed raw materials, designing, and product testing. These differences in the attributes were based on their individualistic application. Furthermore, some of the challenges related to the existing sensors and their possible respective solutions have also been mentioned in the paper. Finally, a market survey has been provided, stating the estimated increase in the annual growth of 3D printed sensors. It also states the type of 3D printing that has been preferred over the years, along with the range of sensors, and their related applications.Published versio

Development of molecular imprinted polymer interdigital sensor for C-terminal telopeptide of type I collagen

This paper presents a label-free and non-invasive technique for selective detection of C-terminal telopeptide type I collagen (CTx-I) by employing Electrochemical Impedance Spectroscopy to measure sample impedance. Molecular imprinted polymer, containing artificial recognition sites for CTx-was prepared by precipitation polymerization using CTx-I peptide as a template, methacrylic acid as a functional monomer and ethylene glycol methacrylate as the cross-linker. A high penetration depth planar interdigital sensor was functionalized by a self-assembled monolayer along with the synthesized MIP. Different concentrations of CTx-I sample solutions were tested using the proposed sensing system. High-Performance Liquid chromatography diode array system was used to validate the results.5 page(s

Laser-Assisted Printed Flexible Sensors: A Review

This paper provides a substantial review of some of the significant research done on the fabrication and implementation of laser-assisted printed flexible sensors. In recent times, using laser cutting to develop printed flexible sensors has become a popular technique due to advantages such as the low cost of production, easy sample preparation, the ability to process a range of raw materials, and its usability for different functionalities. Different kinds of laser cutters are now available that work on samples very precisely via the available laser parameters. Thus, laser-cutting techniques provide huge scope for the development of prototypes with a varied range of sizes and dimensions. Meanwhile, researchers have been constantly working on the types of materials that can be processed, individually or in conjugation with one another, to form samples for laser-ablation. Some of the laser-printed techniques that are commonly considered for fabricating flexible sensors, which are discussed in this paper, include nanocomposite-based, laser-ablated, and 3D-printing. The developed sensors have been used for a range of applications, such as electrochemical and strain-sensing purposes. The challenges faced by the current printed flexible sensors, along with a market survey, are also outlined in this pape

Highly selective ion imprinted polymer based interdigital sensor for nitrite detection

This research proposed the real-time detection of nitrite by employing electrochemical impedance spectroscopy (EIS) technique incorporating an interdigital capacitive sensor. A self-assembled monolayer functionalized the sensing surface with embedded ion-imprinted polymer (IIP) with selectivity for nitrite ions were introduced. Syntheis and characterization of IIP are also explained to validate the polymerization technique. Some initial results using different concentrations of nitrite sample to validate the proposed method are also presented. The promising results highlight the extraordinary potential to develop low-cost, in-situ measurement system to detect nitrite contamination with real-time monitoring.5 page(s

Recent Progress in 3D Printed Mold-Based Sensors

The paper presents a review of some of the significant research done on 3D printed mold-based sensors performed in recent times. The utilization of the master molds to fabricate the different parts of the sensing prototypes have been followed for quite some time due to certain distinct advantages. Some of them are easy template preparation, easy customization of the developed products, quick fabrication, and minimized electronic waste. The paper explains the different kinds of sensors and actuators that have been developed using this technique, based on their varied structural dimensions, processed raw materials, designing, and product testing. These differences in the attributes were based on their individualistic application. Furthermore, some of the challenges related to the existing sensors and their possible respective solutions have also been mentioned in the paper. Finally, a market survey has been provided, stating the estimated increase in the annual growth of 3D printed sensors. It also states the type of 3D printing that has been preferred over the years, along with the range of sensors, and their related applications

A Critical Review of the Use of Graphene-Based Gas Sensors

The employment of graphene for multifunctional uses has been a cornerstone in sensing technology. Due to its excellent electrochemical properties, graphene has been used in its pure and composite forms to detect target molecules over a wide range of surfaces. The adsorption process on the graphene-based sensors has been studied in terms of the change in resistance and capacitance values for various industrial and environmental applications. This paper highlights the performance of graphene-based sensors for detecting different kinds of domestic and industrial gases. These graphene-based gas sensors have achieved enhanced output in terms of sensitivity and working range due to specific experimental parameters, such as elevated temperature, presence of particular gas-specific layers and integration with specific nanomaterials that assist with the adsorption of gases. The presented research work has been classified based on the physical nature of graphene used in conjugation with other processed materials. The detection of five different types of gases, including carbon dioxide (CO2), ammonia (NH3), hydrogen sulphide (H2S), nitrogen dioxide (NO2) and ethanol (C2H5OH) has been shown in the paper. The challenges of the current graphene-based gas sensors and their possible remedies have also been showcased in the paper