A miniaturized optoelectronic biosensor for real-time point-of-care total protein analysis

Ophir Vermesh; Fariah Mahzabeen; Jelena Levi; Marilyn Tan; Israt S. Alam; Carmel T. Chan; Sanjiv S. Gambhir; James S. Harris

MethodsX (Jan 2021)

A miniaturized optoelectronic biosensor for real-time point-of-care total protein analysis

Ophir Vermesh,
Fariah Mahzabeen,
Jelena Levi,
Marilyn Tan,
Israt S. Alam,
Carmel T. Chan,
Sanjiv S. Gambhir,
James S. Harris

Affiliations

Ophir Vermesh: Department of Radiology, Stanford University, Stanford, CA, 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Corresponding authors.
Fariah Mahzabeen: Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
Jelena Levi: Department of Radiology, Stanford University, Stanford, CA, 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA
Marilyn Tan: Department of Medicine, Stanford University, Stanford, CA 94305, USA
Israt S. Alam: Department of Radiology, Stanford University, Stanford, CA, 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA
Carmel T. Chan: Department of Radiology, Stanford University, Stanford, CA, 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA
Sanjiv S. Gambhir: Department of Radiology, Stanford University, Stanford, CA, 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Stanford Bio-X, Stanford University, Stanford, CA 94305, USA
James S. Harris: Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA; Corresponding authors.

Journal volume & issue: Vol. 8
p. 101414

Abstract

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A miniaturized optoelectronic sensor is demonstrated that measures total protein concentration in serum and urine with sensitivity and accuracy comparable to gold-standard methods. The sensor is comprised of a vertical cavity surface emitting laser (VCSEL), photodetector and other custom optical components and electronics that can be hybrid packaged into a portable, handheld form factor. In conjunction, a custom fluorescence assay has been developed based on the protein-induced fluorescence enhancement (PIFE) phenomenon, enabling real-time sensor response to changes in protein concentration. Methods are described for the following: • Standard curves: Used to determine the sensitivity, dynamic range, and linearity of the VCSEL biosensor/PIFE assay system in buffer as well as in human blood and urine samples. • Comparison of VCSEL biosensor performance with a benchtop fluorimetric microplate reader. • Accuracy of the VCSEL biosensor/PIFE assay system: Evaluated by comparing sensor measurements with gold-standard clinical laboratory measurements of total protein in serum and urine samples from patients with diabetes.

VCSEL Biosensor Design and PIFE-Based Total Protein Analysis

Published in MethodsX

ISSN: 2215-0161 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science
Website: http://www.journals.elsevier.com/methodsx/

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