We report a simple, sensitive, and selective electrochemical method for trypsin detection that can cover a wide range of concentrations. The method is based on the proteolytic generation of an electroactive species (P) by trypsin followed by a signal-amplified electrochemical measurement of P using electrochemical-chemical (EC) or electrochemical-chemical-chemical (ECC) redox cycling. The detec...

A glucose electrochemical sensor based on zinc oxide (ZnO) nanorods was investigated. The hydrothermal sol-gel growth method was utilized to grow ZnO nanorods on indium tin oxide-coated glass substrates. The total active area of the working electrode was 0.3 × 0.3 cm2 where titanium metal was deposited to enhance the contact. Well aligned hexagonal structured ZnO nanorods with a diameter from 6...

Urine is the most abundant and easily accessible of all body fluids and provides an ideal route for non-invasive diagnosis of human diseases, particularly of the urinary tract. Electrochemical biosensors are well suited for urinary diagnostics due to their excellent sensitivity, low-cost, and ability to detect a wide variety of target molecules including nucleic acids and protein biomarkers. We...

The electrochemical measurement of the permeation r·ate of hydrogen through metal foils consists of charging of the metal with hydrogen on one side of the foil and removal of hydrogen by electrochemical oxidation on the other side. The hydrogen diffusion coefficient can be determined by mathematical analysis of the time dependence of the oxidation current. This electrochemical technique can als...

Mitochondrial Ca²⁺ uptake contributes important feedback controls to limit the time course of Ca²⁺ signals. Mitochondria regulate cytosolic [Ca²⁺] over an exceptional breath of concentrations (~200 nM to >10 μM) to provide a wide dynamic range in the control of Ca²⁺ signals. Ca²⁺ uptake is achieved by passing the ion down the electrochemical gradient, across the inner mitochondria membrane, whi...

Management and prognosis of diseases requires the measurement in non- or minimally invasively collected samples of specific circulating biomarkers, consisting of any measurable or observable factors in patients that indicate normal or disease-related biological processes or responses to therapy. Therefore, on-site, fast and accurate determination of these low abundance circulating biomarkers in...

Latex micrometric beads are manipulated by optical tweezers in the vicinity of an ultramicroelectrode (UME). They are optically trapped in solution and approached the electrode surface. After the electrochemical measurement, they are optically removed from the surface. The residence time of the particle on the electrode is thus controlled by the optical tweezers. The detection is based on diffu...

Electrochemical impedance spectroscopy is an efficient, non-intrusive and semi-quantitative technique to characterize the performance of bio-electrochemical systems such as microbial fuel cells and enzymatic fuel cells. Indeed, quantitative interpretation of the impedance data can be obtained with the help of mechanistic models using meaningful equivalent circuits. The production of maximum pow...

A surface plasmon resonance imaging system combined with a multielement electrode array is described. An optical system with shaping optics is used to direct a wedge of light onto a gold-coated sample. The reflected light is detected in the form of an angle-spread image of the surface, with one direction denoting a variable incident angle and the other showing a span of locations along one late...

Voltammetric scanning electrochemical cell microscopy (SECCM) incorporates cyclic voltammetry measurements in the SECCM imaging protocol, by recording electrochemical currents in a wide potential window at each pixel in a map. This provides much more information compared to traditional fixed potential imaging. Data can be represented as movies (hundreds of frames) of current (over a surface reg...