Influence of Oxygen Microenvironment on Microfluidic Glucose Sensor Performance

We propose a novel method to overcome significant problems of baseline drift and sensitivity degradation in amperometric biosensors based on oxidase enzyme reactions. A novel glucose microsensor with a built-in electrochemical oxygen manipulation microsystem is introduced to demonstrate three novel functionalities; one-point in situ self-calibration (zero-point), broadening of dynamic range and increase in sensitivity. The influence of electrochemically generated oxygen microenvironment on the sensor output within a fluidic structure is investigated

Oxidase-Coupled Amperometric Glucose and Lactate Sensors with Integrated Electrochemical Actuation System

Unpredictable baseline drift and sensitivity degradation during continuous use are two of the most significant problems of biosensors including the amperometric glucose and lactate sensors. Therefore, the capability of on-demand in situ calibration/diagnosis of biochemical sensors is indispensable for reliable long-term monitoring with minimum attendance. Another limitation of oxidase enzyme-based biosensors is the dependence of enzyme activity on the background oxygen concentration in sample solution. In order to address these issues, the electrolytic generation of oxygen and hydrogen bubbles were utilized 1) to overcome the background oxygen dependence of glucose and lactate sensors and 2) to demonstrate the feasibility of in situ self-calibration of the proposed glucose and lactate sensors. Experimental data assure that the proposed techniques effectively establish the zero calibration value and significantly improve the measurement sensitivity and dynamic range in both glucose and lactate sensors

Glass-Based Biodegradable Pressure Sensor toward Biomechanical Monitoring with a Controllable Lifetime

A New Class of Potentially Implantable Solid-State Sensors is Demonstrated Utilizing Biodegradable Glass as the Main Structural Material. the Device Behavior is Manipulated Via Chemical Decomposition, and Then Physically Disintegrated in a Controlled Manner. It is based on the Capacitive Sensing Mechanism, Comprising an Elastic Insulator between Two Borate-Rich Glass Substrates. This Mesoscale Pressure Sensor is Characterized by a Range of Pressure of Up to 14 MPa in a Phosphate Buffer Solution Environment. the Sensor Exhibits Good Sensitivity and Reversibility Responding to Compressive Pressures and Remains Fully Functional Before a Desired, Sudden Failure Caused by Dissolution. the Operational Lifetime Can Be Modified by Altering the Chemical Composition or Thickness of the Biodegradable Glass Component. the Proposed Device Concept is a Viable Option toward Various Temporary Implantable Devices Without Needing an Additional Surgical Procedure to Remove Them after their Duty

An Intelligent Dissolved Oxygen Microsensor System with Electrochemically Actuated Fluidics

A new dissolved oxygen monitoring microsystem is proposed to achieve in situ intelligent self-calibration by using an electrochemically actuated fluidic system. The electrochemical actuation, based on water electrolysis, plays two critical roles in the proposed microsystem. First, the electrochemically generated gases serve as the calibrants for the in situ 2-point calibration/diagnosis procedure of the microsensor in a chip. Secondly, the electrochemical generation and collapse of gas bubbles provide the driving force of the bidirectional fluidic manipulation for sampling and dispensing of the sample solution. A microsystem including a dissolved oxygen microprobe, electrochemical actuators, and a fluidic structure are prepared by microfabrication technology and its performance is characterized