Handheld impedance biosensor system using engineered proteinaceous receptors

Establish pre-clinical diagnostic efficacy for parathyroid hormone as a point-of-surgery-testing-device (POST)

Measuring the Parathyroid hormone (PTH) levels assists in the investigation and management of patients with parathyroid disorders. Rapid PTH monitoring is a valid tool for accurate assessment intraoperatively. Rapid Electro-Analytical Device (READ) is a point-of-care device that uses impedance change between target and capture probe to assess the PTH concentration in undiluted patient plasma samples. The aim of this work focuses on evaluating the analytical performance of READ platform to Roche analyzer as a prospective clinical validation method. The coefficient of variation (CV) for intra-assay imprecision was < 5% and inter-assay imprecision CV was < 10% for high (942 pg/mL) and low (38.2 pg/mL) PTH concentration. Functional sensitivity defined at 15% CV was 1.9 pg/mL. Results obtained from READ platform correlated well (r = 0.99) with commercially available clinical laboratory method (Roche Diagnostics) to measure PTH concentrations with a turn-around time of less than 15 min. Furthermore, the mean bias of 7.6 pg/mL determined by Bland–Altman analysis, showed good agreement between the two methods. We envision such a sensing system would allow medical practitioners to facilitate targeted interventions, thereby, offering an immediate prognostic approach as the cornerstone to delivering successful treatment for patients suffering from primary hyperparathyroidism.

POISED-5, a portable on-board electrochemical impedance spectroscopy biomarker analysis device

Point-of-care medical devices offer the potential for rapid biomarker detection and reporting of medical conditions, thereby bypassing the requirements for offline clinical laboratory facilities in many cases. Label-free electrochemical techniques are suitable for use in handheld diagnostic devices due the inherent electronic detection modality and low requirement for processing reagents. While electrochemical impedance sensing is widely used in tissue analysis such as body composition measurement, its use in point-of-care patient testing is yet to be widely adopted. Here we have considered a number of issues currently limiting the translation of electrochemical impedance sensing into clinical biosensor devices. Specifically, we have addressed the current requirement for these sensors to be connected to an external processor by applying a minimum number of frequencies required for optimized biomarker detection, and subsequently delivering analytics within the measurement device. The POISED-5 device was evaluated using a sensor for the ovarian cancer biomarker cancer antigen 125 (CA125), demonstrating performance comparable to standard laboratory equipment, with direct interpretation of response signal amplitude substituting traditional impedance component calculation and model fitting.

Interfacial capacitance immunosensing using interdigitated electrodes: the effect of insulation/immobilization chemistry

With the aim of improving the reproducibility of capacitive immunosensors, we performed a comparative study of four different insulating/immobilization chemistries.

Cytotoxicity of synthesized Iron Oxide nanoparticles: toward novel biomarkers of colon cancer

In this paper we present the preliminary results of a novel biological analysis platform for early colon cancer detection using magnetic separation of magnetized markers. The platform consists of a microfluidic structure integrated with biosensors. Super-Paramagnetic Iron Oxide nanoparticles (SPIO-NPs) were functionalized with purified DNA Aptamer and their synthesis is described. In this paper, we also present the physicochemical results of the synthesized SPIO/Au-NPs characterized by TEM and XRD. Toxicity of our synthesized biomarkers on HCT116 cell line is discussed. Based on our findings, a concentration of 1mg/ml of our biomarkers added to 5 × 105 cells per well has no effect the viability of the human cells even after 24 hours.

Toward implantable glucometer: design, modeling and experimental results

We put forward an implantable glucometers using a biologically inspired sensor (BioS) method. In this method, engineered glucokinase (GLK) molecules are used as nanoscale glucometers. Herein, we describe two computational and experimental models of GLKs exposed to glucose molecules. The simulation results significantly show the detection of GLK binding to glucose. We thereafter reveal the applicability of this technique for continuous glucose monitoring by demonstrating and discussing the experimental results. Based on these results the glucose measurement with various glucose concentrations (0.5 mM, 1 mM and 2.5 mM) were precisely performed and repeated for more than 4 weeks. These results prove the advantage of proposed BioS method for continuous measurement of glucose.

A New Fully Differential CMOS Capacitance to Digital Converter for Lab-on-Chip Applications

In this paper, we present a new differential CMOS capacitive sensor for Lab-on-Chip applications. The proposed integrated sensor features a DC-input ΣΔ capacitance to digital converter (CDC) and two reference and sensing microelectrodes integrated on the top most metal layer in 0.35 μm CMOS process. Herein, we describe a readout circuitry with a programmable clocking strategy using a Charge Based Capacitance Measurement technique. The simulation and experimental results demonstrate a high capacitive dynamic range of 100 fF-110 fF, the sensitivity of 350 mV/fF and the minimum detectable capacitance variation of as low as 10 aF. We also demonstrate and discuss the use of this device for environmental applications through various chemical solvents.

Wireless integrated biosensors for point-of-care diagnostic applications

Recent advances in integrated biosensors, wireless communication and power harvesting techniques are enticing researchers into spawning a new breed of point-of-care (POC) diagnostic devices that have attracted significant interest from industry. Among these, it is the ones equipped with wireless capabilities that drew our attention in this review paper. Indeed, wireless POC devices offer a great advantage, that of the possibility of exerting continuous monitoring of biologically relevant parameters, metabolites and other bio-molecules, relevant to the management of various morbid diseases such as diabetes, brain cancer, ischemia, and Alzheimer's. In this review paper, we examine three major categories of miniaturized integrated devices, namely; the implantable Wireless Bio-Sensors (WBSs), the wearable WBSs and the handheld WBSs. In practice, despite the aforesaid progress made in developing wireless platforms, early detection of health imbalances remains a grand challenge from both the technological and the medical points of view. This paper addresses such challenges and reports the state-of-the-art in this interdisciplinary field.