Independently-addressable micron-sized biosensor elements

Davis, C.; Shamansky, Lisa M.; Rosenwald, Steven E.; Stuart, Joan K.; Kuhr, Werner G.; Brazill, Sara A.

doi:10.1016/s0956-5663(03)00071-x

Cited by 20 publications

(2 citation statements)

References 37 publications

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“…There is a growing demand for array-based biosensors in order to realize rapid and high-throughput analyses. 1,2) Fluorescence measurement with high sensitivity and a variety of commercially available tools has already been developed. However, there are two drawbacks: performance degradation due to shielding by a turbid solution or vessels, and the necessity for labeling non-fluorescent species.…”

Section: Introductionmentioning

confidence: 99%

Amperometric electrochemical sensor array for on-chip simultaneous imaging

Kuno

Niitsu

Nakazato

2014

Jpn. J. Appl. Phys.

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We propose an amperometric electrochemical sensor array for high-speed measurement of microelectrode currents. The biosensor was fabricated using CMOS technology and a contact photolithographic process to incorporate gold microelectrodes (256 electrodes) on a chip. The sensor circuit employed a current buffer circuit and dual switch. During measurement, all electrodes were kept at a constant potential, currents were at steady-state levels, and rapid switching was performed while maintaining the steady-state current. The measured current range of the current buffer circuit was approximately 1 pA to 1 µA. A microelectrode array (MEA) with auxiliary electrode (AE) was used to suppress expansion of the diffusion layer over the MEA. Steady-state current was obtained and amplified by redox cycling, greatly reducing the time for reaching the steady-state level. The sensor successfully simultaneously measured multipoint cyclic voltammetry and amperometry, and will be useful for measuring local concentration and analyzing the diffusion processes of target molecules.

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Section: Introductionmentioning

confidence: 99%

Amperometric electrochemical sensor array for on-chip simultaneous imaging

Kuno

Niitsu

Nakazato

2014

Jpn. J. Appl. Phys.

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“…The development of array-based biosensors has received considerable attention due to the strong demand for rapid and high-throughput analyses. 1,2) Fluorescent techniques employ light sources and photomultiplier tubes or chargecoupled device (CCD) cameras that excite the fluorophores and detect the emitted light. However, these techniques have some drawbacks such as shielding by a turbid solution or vessels, as well as the need to label nonfluorescent species.…”

Section: Introductionmentioning

confidence: 99%

Amperometric Electrochemical Sensor Array for On-Chip Simultaneous Imaging: Circuit and Microelectrode Design Considerations

Hasegawa¹,

Uno²,

Nakazato³

2011

Jpn. J. Appl. Phys.

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We propose a switching circuit and an electrode design for measuring multiple microelectrode currents at high speed. Our goal is to realize two-dimensional (2D) imaging of analyte distributions by amperometry. In the proposed amperometric sensor circuit, each electrode is connected to two switches. During measurement, the potential of all electrodes is fixed, the steady-state current is maintained, and the switching is carried out while maintaining the steady-state current. A current buffer circuit was fabricated, its the characteristics were evaluated. The time course of the electrochemical current of an electrolyte was measured using the current buffer circuit. We have also proposed a microelectrode structure to suppress the expansion of the diffusion layer over the microelectrode array. Each electrode has a steady-state current, which is amplified by a redox cycle, and the time to reach the steady state is reduced to about 1/10 of that required by a single microelectrode. The relation between the characteristic lengths of the electrode geometry and the current gain is presented.

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