Label-free, ultrasensitive and rapid detection of FDA-approved TBI specific UCHL1 biomarker in plasma using MWCNT-PPY nanocomposite as bio-electrical transducer: A step closer to point-of-care diagnosis of TBI

Supraja, P. and Tripathy, S. and Vanjari, Siva Rama Krishna and Singh, S.G. (2022) Label-free, ultrasensitive and rapid detection of FDA-approved TBI specific UCHL1 biomarker in plasma using MWCNT-PPY nanocomposite as bio-electrical transducer: A step closer to point-of-care diagnosis of TBI. Biosensors and Bioelectronics, 216. pp. 1-12. ISSN 0956-5663

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Abstract

Traumatic Brain Injury (TBI), a major cause of mortality and neurological disability affecting people of all ages worldwide, remains a diagnostic and therapeutic challenge to date. Rapid, ultra-sensitive, selective, and wide-range detection of TBI biomarkers in easily accessible body fluids is an unmet clinical need. Considering this, in this work, we report the design and development of a facile, label-free, highly stable and sensitive, chemi-impedance-based sensing platform for rapid and wide range detection of Ubiquitin-carboxy terminal hydrolase L1 (UCHL1: FDA-approved TBI specific plasma biomarker), using carboxylic functionalized MWCNTs embedded polypyrrole (PPY) nanocomposites (PPY/f-MWCNT). The said nanocomposites were synthesized using chemical oxidative polymerization method. Herein, the functionalized MWCNTs are used as conducting fillers so as to increase the polymer's dielectric constant according to the micro-capacitor model, thereby augmenting both DC electrical conductivity and AC dielectric property of the nanocomposite. The proposed immunosensing platform comprises of PPY/f-MWCNT modified interdigitated microelectrode (IDμEs) array, on which anti-UCHL1-antibodies are immobilized using suitable covalent chemistry. The AC electrical characterization of the nanocomposite modified IDμEs, with and without the antibodies, was performed through generic capacitance vs. frequency (C–F, 1 KHz – 1 MHz) and capacitance vs. applied bias (C–V, 0.1 V–1 V) measurements, using an Agilent B1500A parametric analyzer. The binding event of UCHL1 peptides to anti-UCHL1-antibodies was transduced in terms of normalised changes in parallel capacitance, via the C–F analysis. Further, we have tested the detection efficiency of the said immunoassay against UCHL1 spiked human plasma samples in the concentration range 10 fg/mL – 1 μg/mL. The proposed sensing platform detected UCHL1 in spiked-plasma samples linearly in the range of 10 fg/mL – 1 ng/mL with a sensitivity and LoD of 4.22 ((ΔC/C0)/ng.mL−1)/cm2 and 0.363 fg/mL, respectively. Further, it showed excellent stability (30 weeks), repeatability, reproducibility, selectivity and interference-resistance. The proposed approach is label-free, and if desired, can be used in conjunction with DC measurements, for biosensing applications. © 2022 Elsevier B.V.

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IITH Creators:

IITH Creators	ORCiD
Vanjari, Siva Rama Krishna	UNSPECIFIED
Singh, Shiv Govind	http://orcid.org/0000-0001-7319-879X

Item Type:

Article

Additional Information:

The authors acknowledge the Department of Science and Technology (Fund for Improvement of S&T infrastructure) the Government of India for funding research.

Uncontrolled Keywords:

AC analysis, Array of interdigitated microelectrodes, Chemi-impedance, MWCNT-COOH embedded PPY, TBI, UCHL1-Plasma

Subjects:

Electrical Engineering

Divisions:

Department of Electrical Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

30 Aug 2022 09:50

Last Modified:

30 Aug 2022 09:50