Cytokine and Cancer Biomarkers Detection: The Dawn of Electrochemical Paper-Based Biosensor.

Although the established ELISA-based sensing platforms have many benefits, the importance of cytokine and cancer biomarkers detection for point-of-care diagnostics has propelled the search for more specific, sensitive, simple, accessible, yet economical sensor. Paper-based biosensor holds promise for future in-situ applications and can provide rapid analysis and data without the need to conduct in a laboratory. Electrochemical detection plays a vital role in interpreting results obtained from qualitative assessment to quantitative determination.

Aptamer-based array electrodes for quantitative interferon-γ detection.

Present work describes the methylene blue tagged thiolated aptamer-modified gold micro-array based biosensor for specific detection of IFN-γ. The microchips with the microelectrode array were fabricated using standard silicon microfabrication technologies, and modified with methylene blue tagged aptamer using standard gold thiol chemistry. Electrodes were characterized and tested using Cyclic Voltammetric (CV) and Square Wave Voltammetry (SQW) measurements in a standard three-electrode format at room temperature.

Electrokinetic Analysis of Cell Translocation in Low-Cost Microfluidic Cytometry for Tumor Cell Detection and Enumeration.

Conventional Coulter counters have been introduced as an important tool in biological cell assays since several decades ago. Recently, the emerging portable Coulter counter has demonstrated its merits in point of care diagnostics, such as on chip detection and enumeration of circulating tumor cells (CTC). The working principle is based on the cell translocation time and amplitude of electrical current change that the cell induces.

Effects of the electrode size and modification protocol on a label-free electrochemical biosensor.

In the present work, the effect of a surface modification protocol along with the electrode size has been investigated for developing an efficient, label-free electrochemical biosensing method for diagnosis of traumatic brain injury (TBI) biomarkers. A microdisk electrode array (MDEA) and a macroelectrode with a comb structure (MECS) were modified with an anti-GFAP (GFAP = glial fibrillary acidic protein) antibody using two protocols for optimum and label-free detection of GFAP, a promising acute-phase TBI biomarker. For the MDEA, an array of six microdisks with a 100 μm diameter and, for the MECS, a 3.

3D numerical simulation of a Coulter counter array with analysis of electrokinetic forces.

Coulter counters have played an important role in biological cell assays since their introduction decades ago. Several types of high throughput micro-Coulter counters based on lab-on-chip devices have been commercialized recently. In this paper, we propose a highly integrated micro-Coulter counter array working under low DC voltage.

Nanoelectronic detection of triggered secretion of pro-inflammatory cytokines using CMOS compatible silicon nanowires.

Nanotechnology, such as nanoelectronic biosensors, is bringing new opportunities and tools to the studies of cell biology, clinical applications, and drug discovery. In this study, crystalline silicon nanowire based field-effect transistors fabricated using top-down approach were employed to parallelly detect pro-inflammatory cytokines in the complex biological fluids (cell culture medium and blood samples) with high specificity and femtomolar sensitivity. Using this technique, the dynamic secretion of TNF-alpha and IL6 was revealed during the immune response of macrophages and rats to the stimulation of bacteria endotoxin.

Ultra-sensitive detection of adipocytokines with CMOS-compatible silicon nanowire arrays.

Perfectly aligned arrays of single-crystalline silicon nanowires were fabricated using top-down CMOS-compatible techniques. We demonstrate that these nanowire devices are able to detect adipocytokines secreted by adipose cells with femtomolar sensitivity, high specificity, wide detection range, and ability for parallel monitoring. The nanowire sensors also provide a novel tool to reveal the poorly understood signaling mechanisms of these newly recognized signaling molecules, as well as their relevance in common diseases such as obesity and diabetes.