Microfluidic device with photodiodes with controllable shunts to detect fluorescing hybridized probes

Abstract

A microfluidic device for detecting a target nucleic acid sequence, the microfluidic device having a probe for hybridization with the target nucleic acid sequence to form a probe-target hybrid, the probe having a fluorophore for generating fluorescence emissions in response to an excitation light, a photodiode for detecting the fluorescence emissions, a shunt transistor between the photodiode and a voltage source, and, CMOS circuitry for controlling the shunt transistor to remove carriers generated by absorption of photons of the excitation light in the photodiode.

Description

FIELD OF THE INVENTION[0001]The present invention relates to diagnostic devices that use microsystems technologies (MST). In particular, the invention relates to microfluidic and biochemical processing and analysis for molecular diagnostics.CO-PENDING APPLICATIONS[0002]The following applications have been filed by the Applicant which relate to the present application:GBS001USGBS002USGBS003USGBS005USGBS006USGSR001USGSR002USGAS001USGAS002USGAS003USGAS004USGAS006USGAS007USGAS008USGAS009USGAS010USGAS012USGAS013USGAS014USGAS015USGAS016USGAS018USGAS019USGAS020USGAS021USGAS022USGAS023USGAS024USGAS025USGAS026USGAS027USGAS028USGAS030USGAS031USGAS032USGAS033USGAS034USGAS035USGAS036USGAS037USGAS038USGAS039USGAS040USGAS041USGAS042USGAS043USGAS044USGAS045USGAS046USGAS047USGAS048USGAS049USGAS050USGAS054USGAS055USGAS056USGAS057USGAS058USGAS059USGAS060USGAS061USGAS062USGAS063USGAS065USGAS066USGAS067USGAS068USGAS069USGAS070USGAS080USGAS081USGAS082USGAS083USGAS084USGAS085USGAS086USGAS087USGAS088USGAS...

AI Technical Summary

Benefits of technology

[0092]Photosensors with controllable shunts obviate the need for any wavelength dependent filter components, making the design inexpensive, small, and light.

Problems solved by technology

Insufficient stringency can result in a high degree of nonspecific binding.

Excessive stringency can lead to a failure of appropriate binding, which results in diminished sensitivity.

Despite the advantages that molecular diagnostic tests offer, the growth of this type of testing in the clinical laboratory has been slower than expected and remains a minor part of the practice of laboratory medicine.

This is primarily due to the complexity and costs associated with nucleic acid testing compared with tests based on methods not involving nucleic acids.

However, controlling fluid flow through the LOC device, adding reagents, controlling reaction conditions and so on necessitate bulky external plumbing and electronics.

Connecting a LOC device to these external devices effectively restricts the use of LOC devices for molecular diagnostics to the laboratory setting.

The cost of the external equipment and complexity of its operation precludes LOC-based molecular diagnostics as a practical option for point-of-care settings.

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