Divalent ion-induced aggregation of gold nanoparticles for voltammetry Immunosensing: comparison of transducer signals i

  • PDF / 1,124,403 Bytes
  • 9 Pages / 595.276 x 790.866 pts Page_size
  • 21 Downloads / 199 Views

DOWNLOAD

REPORT


ORIGINAL PAPER

Divalent ion-induced aggregation of gold nanoparticles for voltammetry Immunosensing: comparison of transducer signals in an assay for the squamous cell carcinoma antigen Iswary Letchumanan 1 & Subash C. B. Gopinath 1,2

&

M. K. Md Arshad 1,3

Received: 11 August 2019 / Accepted: 3 January 2020 # Springer-Verlag GmbH Austria, part of Springer Nature 2020

Abstract A method is described for the electrochemical determination of squamous cell carcinoma (SCC) antigen, and by testing the effect of 30 nm gold nanoparticles (GNPs). Three comparative studies were performed in the presence and absence of GNPs, and with agglomerated GNPs. The divalent ion Ca(II) was used to induce a strong agglomeration of GNPs, as confirmed by colorimetry and voltammetry. Herein, colorimetry was used to test the best amount of salt needed to aggregate the GNPs. Despite, voltammetry was used to determine the status of biomolecules on the sensor. The topography of the surface of ZnO-coated interdigitated electrodes was analyzed by using 3D-nano profilometry, scanning electron microscopy, atomic force microscopy and high-power microscopy. The interaction between SCC antigen and antibody trigger vibrations on the sensor and cause dipole moment, which was measured using a picoammeter with a linear sweep from 0 to 2 V at 0.01 V step voltage. The sensitivity level was 10 fM by 3σ calculation for the dispersed GNP-conjugated antigen. This indicates a 100-fold enhancement compared to the condition without GNP conjugation. However, the sensitivity level for agglomerated GNPs conjugated antibody was not significant with 100 fM sensitivity. Specificity was tested for other proteins in serum, namely blood clotting factor IX, C-reactive protein, and serum albumin. The SCC antigen was quantified in spiked serum and gave recoveries that ranged between 80 and 90%. Keywords Dielectric sensing . Zinc oxide . Interdigitated electrode . Colorimetry . Agglomeration . Dispersion . Blood disease . Cancer . Biosensor

Introduction Squamous Cell Carcinoma (SCC) has been found to associate with various kinds of skin carcinoma, one of the world’s most common diseases and the second largest form of skin carcinoma [1–3]. There are several types of SCC, which can be Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00604-020-4115-0) contains supplementary material, which is available to authorized users. * Subash C. B. Gopinath [email protected] 1

Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, 01000 Kangar, Perlis, Malaysia

2

School of Bioprocess Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia

3

School of Microelectronic Engineering, Universiti Malaysia Perlis, Pauh Putra, 02600 Arau, Perlis, Malaysia

categorized based on the anatomical location where cancer appears and often found in head, skin, cervix, esophagus, neck and lung and rarely noticed in pancreas, thyroid, prostate and bladder [4]. It was reported that SCC antigen (SCC-Ag) is the best biomarker