Protein detecting with smartphone-controlled electrochemical impedance spectroscopy for point-of-care applications

This paper reports the successful fabrication of an impedance-based miniaturized biosensor and its application for ultrasensitive Prostate-Specific Antigen (PSA) detection in standard and real human plasma solution, spiked with different PSA concentrations. The sensor was fabricated using photolithographic techniques, while monoclonal antibodies specific to human PSA were used as primary capture antibodies. Electrochemical impedance spectroscopy (EIS) was employed as a detection technique. The sensor exhibited a detection limit of 1 pg/ml for PSA with minimal nonspecific binding (NSB). This detection limit is an order of magnitude lower than commercial PSA ELISA assays available on the market. The sensor can be easily modified into an array for the detection of other biomolecules of interest, enabling accurate, ultrasensitive, and inexpensive point-of-care sensing technologies.

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A point of care electrochemical impedance spectroscopy device

2015 28th IEEE International System-on-Chip Conference (SOCC) ◽

10.1109/socc.2015.7406955 ◽

2015 ◽

Cited By ~ 3

Author(s):

Zhijian Lu ◽

Hongyi Wang ◽

Syed Roomi Naqvi ◽

Houqiang Fu ◽

Yuji Zhao ◽

...

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Point Of Care

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A Graphene-PEDOT:PSS Modified Paper-Based Aptasensor for Electrochemical Impedance Spectroscopy Detection of Tumor Marker

Sensors ◽

10.3390/s20051372 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1372 ◽

Cited By ~ 4

Author(s):

Yi-Kuang Yen ◽

Chen-Hsiang Chao ◽

Ya-Shin Yeh

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Point Of Care ◽

Low Cost ◽

Serum Samples ◽

Analytical Instruments ◽

Buffer Solutions ◽

Early Cancer Diagnosis

A graphene and poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) modified conductive paper-based electrochemical impedance spectroscopy (EIS) aptasensor has been successfully fabricated by a simple and continuous coating process. A graphene/PEDOT:PSS modified paper electrode forms the nanocomposite providing a conductive and sensitive substrate for further aptamer functionalization of the biosensor. This low-cost paper-based aptasensor exhibits its sensitivity to carcinoembryonic antigens (CEA) in standard buffer solutions and human serum samples in a linear range of 0.77–14 ng·mL−1. The limit of detection (LOD) is found to be 0.45 ng·mL−1 and 1.06 ng·mL−1 for CEA in both samples, separately. This aptamer-based sensing device was also evaluated and received a good correlation with the immunoassay detection method. The proposed paper-based aptasensor has demonstrated its potential as a rapid simple point-of-care analytical platform for early cancer diagnosis in less developed areas where manufacturing facilities, analytical instruments, and trained specialists are limited.

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