Comparison of the Accuracy of Noninvasive Hemoglobin Sensor (NBM-200) and Portable Hemoglobinometer (HemoCue) with an Automated Hematology Analyzer (LH500) in Blood Donor Screening

BACKGROUND: The Hb levels of prospective blood donors are usually determined using a finger prick test. A new noninvasive Hb device has the advantage of not causing any sampling pain. The purpose of this study was to evaluate the accuracy of the noninvasive Hb sensor and to compare its measurements with those of a currently used portable hemoglobinometer. METHODS: Hb was measured using a noninvasive Hb sensor (NBM-200; OrSense, Israel), a portable hemoglobinometer (HemoCue; HemoCue AB, Sweden), and an automated hematology analyzer (LH500; Beckman Coulter, USA). The correlations between Hb measurements taken by the NBM-200 and HemoCue with those by an automated hematology analyzer were assessed using intraclass correlation coefficients (ICCs). Hb measurements were compared among 3 different Hb level groups. RESULTS: The mean Hb values of 506 blood donors were 14.1 g/dL by the NBM-200, 14.0 g/dL by the LH500, and 14.3 g/dL by the HemoCue. The correlation between the LH500 and the NBM-200 was substantial (ICC=0.69), while that between the LH500 and the HemoCue agreed almost perfectly (ICC=0.86). CONCLUSIONS: The possibility to judge to be eligible for donors who are ineligible to donate was substantial when using NBM-200. Even though the NBM-200 has the apparent advantage of noninvasiveness, its use in pre-screening should be given meticulous attention. Since pre-donation testing is crucial to protecting donors' health, complete evaluation of the instrument should be performed prior to use.

An amperometric cholesterol biosensor based on epoxy resin membrane bound cholesterol oxidase.

Background & objectives: The use of epoxy resin membrane as a support for immobilization of enzyme has resulted into improved sensitivity and stability of biosensors for uric acid, ascorbic acid and polyphenols. The present work was aimed to prepare an improved amperometric biosensor for determination of serum cholesterol required in the diagnostics and management of certain pathological conditions. Methods: Epoxy resin membrane with immobilized cholesterol oxidase was mounted on the cleaned platinum (Pt) electrode with a parafilm to construct a working electrode. This working electrode along with Ag/AgCl as reference and Ag wire as an auxiliary electrode were connected through a three terminal electrometer to construct a cholesterol biosensor. Results: The sensor showed optimum response within 25 sec at pH 7.0 and 45°C. The linear working range of biosensor was 1.0 to 8.0 mM cholesterol. Km and Imax for cholesterol were 5.0 mM and 9.09 μA, respectively. The biosensor measured serum cholesterol. The minimum detection limit of the sensor was 1.0 mM. The mean analytical recoveries of added cholesterol in serum (2.84 and 4.13 mM) were 91.4±2.8 and 92.3±3.1 per cent (n=6), respectively. Within and between assay coefficient of variation (CV) were <2 and <4 per cent, respectively. Biosensor had a storage life of 6 months at 4°C. Interpretation & conclusions: The use of epoxy resin membrane as a support for immobilization of cholesterol oxidase has resulted into an improved amperometric cholesterol biosensor. The present biosensor had an advantage over the existing biosensors as it worked at comparatively lower potential.

Electrochemical biosensors in pharmaceutical analysis / Biossensores eletroquímicos em análise farmacêutica

Given the increasing demand for practical and low-cost analytical techniques, biosensors have attracted attention for use in the quality analysis of drugs, medicines, and other analytes of interest in the pharmaceutical area. Biosensors allow quantification not only of the active component in pharmaceutical formulations, but also the analysis of degradation products and metabolites in biological fluids. Thus, this article presents a brief review of biosensor use in pharmaceutical analysis, focusing on enzymatic electrochemical sensors.

Em virtude do aumento da demanda por técnicas analíticas simples e de baixo custo, os biossensores têm atraído a atenção para a análise de fármacos, medicamentos e outros analitos de interesse em controle de qualidade de medicamentos. Os biossensores permitem a quantificação não somente de princípio ativo em formulações farmacêuticas, mas também de produtos de degradação e metabólitos em fluídos biológicos, bem como análise de amostras de interesse clínico e industrial, além de possibilitar a determinação de enantiômeros. Desta forma, este artigo objetiva fazer uma breve revisão a respeito do emprego de biossensores em análise farmacêutica, com ênfase em sensores eletroquímicos enzimáticos.

Medical applications of nanotechnology.

In the true spirit of interdisciplinary expansion of scientific knowledge, results from the applicability of nanotechnology in the fields of physical sciences and chemistry have now matured enough to extend into biology and medicine. The advances in nanotechnology in the past decade have offered novel opportunities for sensing clinically relevant markers, molecular dsease imaging and tools for therapeutic intervention, which have a potential to transform the field of medicine. We describe the currently available components of the nano-toolbox, which are likely to be incorporated in clinical practice in the forseeable future. These include nanowires, cantilevers and nanopores for sensing, naoparticles and quantum dots for molecular imaging and nanoparticles for therapy. We also discuss the issue of toxicity of these nanomaterials and other limitations in the application of nanotechnology to medicine.

Preparation of micro-biosensor and its application in monitoring in vivo change of dopamine / 华中科技大学学报（医学）（英德文版）

The self-made high sensitivity and selectivity micro-biosensor was applied to monitor the change of dopamine in cerebral nucleus in rats in vivo. The micro-biosensor was prepared and used to detect dopamine level in vitro and monitor the dynamic change of dopamine in different cerebral nucleus in vivo. The results showed the lowest concentration of dopamine that could be detected by the biosensor was 32.5 nmol/L. Its positive peak was significantly different from that of AA, 5-HTP and E. The biosensor could keep working for monitoring the dopamine concentration in the cerebral tissue for more than 10 h. It was concluded that the microsensor has high sensitivity and selectivity to dopamine and can be used to dynamically monitor the change of dopamine in vivo.

Uso de gelatina comercial en el desarrollo de un biosensor de ureasa inmovilizada / Use of commercial gelatine in the development of a biosensor of ureasa inmovilized

Introducción: Diferentes matrices han sido ensayadas en la elaboración de biosensores. En este trabajo, se describe un biosensor a ureasa inmovilizada utilizando gelatina comercial como matriz soporte, conectado a un sistema de flujo semiautomático para optimizar el proceso. Material y métodos: Para la inmovilización enzimática se utilizó como matriz gelatina comercial, y como agente polimerizador, el glutaraldehído. Se analizó el efecto de diversos sistemas buffer para la gelificación de la matriz. Para la construcción del biosensor se incorporó una alícuota de enzimas inmovilizadas en un cartucho Mobicol de 1 ml, el cual se acopló a un sistema de control de flujo semi-automático, valorándose el flujo óptimo para una apropiada relación enzima-substrato. Resultados y conclusiones: Se logró un óptimo entrampado del enzima a una concentración de ureasa de 0,4 mg/ml en gelatina disuelta en solución buffer fosfato 100mM pH=7,2 (25 mg/ml), con agregado de glutaraldehído al 1,2 por ciento (v/v) como agente polimerizador. La temperatura y flujo más apropiados para la reacción fueron 37°C y 0,035 ml/min., respectivamente. La actividad específica del enzima inmovilizada mostró linealidad con el enzima soluble, y el porcentaje de inmovilización alcanzó un 46 por ciento.