An electron transfer mediator, 8-dimethylamino-2,3-benzophenoxazine (Meldola Blue), dissolved in the carrier solution in a flow-injection system, was found to reduce the oxidation potential for hydrogen peroxide from 600-1200 mV without mediator to - 100 mV vs. Ag/AgCl with the mediator present. The very low background current of reticulated vitreous carbon (RVC) at this potential makes it possibl

An integrated thermal biosensor array was designed and fabricated for the simultaneous determination of glucose, urea and penicillin. The sensor contains six thin-film thermistors which were fabricated on quartz chip by micromachining and semiconductor technology. This sensor allows the determination of three different analytes nearly simultaneously by serially partitioning a single microchan

A flow injection thermal microbiosensor was designed for the simultaneous determination of multiple analytes. The biosensor consisted of five thin-film thermistors which were located along a single microchannel. The device was fabricated on a quartz chip by micromachining. The feasibility of employing this system for the detection of two independent enzyme reactions was demonstrated using two diff

A miniaturized thermal flow injection analysis biosensor has been coupled with a microdialysis probe for continuous subcutaneous glucose monitoring. Thermal biosensors are based on the principle of measuring the heat evolved during enzyme catalysed reactions. The system presented here consists of a miniaturized thermal biosensor with a small column containing coimmibolized glucose oxidase and

A miniaturized flow-injected thermal biosensor was developed for the determination of urea and L-lactate in undiluted blood in 1-μL samples. The sensor employed a small enzyme column constructed of stainless steel tubing and microbead thermistors. Urease and lactate oxidase/catalase were separately immobilized onto controlled-pore glass beads, which, in turn, were charged into the enzyme column. W

A microbiosensor based on an integrated thermopile was designed and fabricated on a quartz chip. The thermopile, which was manufactured by doping boron in polysilicon together with aluminium, provided a potential output of ca. 2 mV K. A silicone rubber membrane was used to form and seal the microchannel. The total column volume was 20 μl. Glucose oxidase and catalase were co-immobilized on spheric

The glucose concentration in diluted whole blood has been measured, using a miniaturized thermal biosensor based on the enzyme thermistor principle. The biosensor is a small flow injection system. A sample volume of 20μl is injected into a flow of 50μ1/min. The heat produced when the sample passes the enzyme column is measured with a thermistor connected to a Wheatstone bridge. The enzyme column c

Miniaturized thermal biosensors based on three different designs have been constructed. Properties relevant to decentralized bioanalysis have been investigated. A short measurement period (30 s per sample) and a broad linear range (0.5 mM to 100 mM for glucose and penicillin-V), using 1 μl sample volume, have been achieved.

Fast determination of whole blood glucose without any pretreatment was achieved using a calorimetric FIA micro-biosensor. Glucose oxidase was covalently immobilized, together with catalase, onto controlled pore glass beads and packed into a micro-column. By reducing the sample volume down to 1 μ1, a measurement period of about 40 s and an enlarged linear range of 0.5-20 mM glucose were obtained. T

Malignant breast tumours can be distinguished from benign lesions and normal tissue based on their mechanical properties. Our pilot studies have demonstrated the potential of using Mechanical Imaging (MI) combined with mammography to reduce recalls and false positives in breast cancer screening by more accurately identifying benign lesions. To enable further optimization of MI we propose a compute

A biosensor that combines electrochemistry and calorimetry was investigated. Using this sensor, glucose measurements were performed by employing glucose oxidase together with ferrocene as electron-transfer mediator. The electrochemical reaction was accomplished by applying a voltage between a platinum column (working electrode), in contact with a crushed reticulated vitreous carbon (RVC) matrix on

In order to develop a sensitive, versatile and inexpensive portable instrument, a calorimetric micro-biosensor was designed and fabricated by etching part of the flow system into a silicon wafer. The utility of the device was tested using the enzymes, catalase and penicillinase. This sensor showed good reproducibility and linearity up to 100 mM. The system also showed higher sensitivity than the c

New applications of a flow-calorimetric biosensor system, the enzyme thermistor (ET) are described. The ET measures the reaction heat in a small column containing immobilized biocatalyst as a temperature change of the effluent from the column. Since most biological reactions are exothermic, the ET has a very broad applicability and numerous assays of clinical as well as biotechnological interest h

A newly designed thermal biosensor (TBS) is reported. It is constructed by integrating a temperature sensor with a bioreactor, which can be easily dismantled. Such a design makes the TBS versatile. Both differential and adiabatic techniques are used to improve its precision and resolution. As an example of application, a glucose assay is described: resolution 2 × 10-8 mol, linear range 2 × 10-8 mo