Next Article in Journal
SNDR Limits of Oscillator-Based Sensor Readout Circuits
Previous Article in Journal
Speed Bump Detection Using Accelerometric Features: A Genetic Algorithm Approach
Previous Article in Special Issue
Trends and Advances in Electrochemiluminescence Nanobiosensors
Open AccessArticle

Electrochemical Immunoassay Using Open Circuit Potential Detection Labeled by Platinum Nanoparticles

1
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi City, Ishikawa 923-1292, Japan
2
Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok 10330, Thailand
3
National Center of Excellent of Petroleum, Petrochemicals and Advanced Materials, Chulalongkorn University, Patumwan, Bangkok 10330, Thailand
*
Authors to whom correspondence should be addressed.
Sensors 2018, 18(2), 444; https://doi.org/10.3390/s18020444
Received: 28 December 2017 / Revised: 18 January 2018 / Accepted: 1 February 2018 / Published: 3 February 2018
In this work, a simple electrochemical immunoassay based on platinum nanoparticles (PtNPs) using open circuit potential (OCP) detection was developed. The detection of human chorionic gonadotropin hormone (hCG) as a model analyte, was demonstrated by direct electrical detection of PtNPs in hydrazine solution using OCP measurement without any application of either potential or current to the system. Disposable screen-printed carbon electrodes (SPCEs) were utilized for the development of our immunosensor, which required a sample volume as small as 2 μL. After preparation of a sandwich-type immunosystem, hydrazine solution was dropped on the electrode’s surface, which was followed immediately by electrical detection using OCP. The change of the OCP signal originated from electrocatalytic oxidation of the hydrazine on PtNPs. Under the optimal conditions of a pH of 6.0 and a hydrazine concentration of 1 mM, a detection limit of 0.28 ng mL−1 and a linearity of 0–10 ng mL−1 were obtained. The PtNP-based OCP method is a simpler electrochemical detection procedure than those obtained from other electrochemical methods and has an acceptable sensitivity and reproducibility. The simplicity of the detection procedure and the cost-effectiveness of the disposable SPCE illustrate the attractive benefits of this sensor. Moreover, it could be applied to a simplified and miniaturized diagnostic system with minimal user manipulation. View Full-Text
Keywords: human chorionic gonadotropin; screen-printed carbon electrode; platinum nanoparticles; open circuit potential; electrochemical immunosensor human chorionic gonadotropin; screen-printed carbon electrode; platinum nanoparticles; open circuit potential; electrochemical immunosensor
Show Figures

Figure 1

MDPI and ACS Style

Charoenkitamorn, K.; Tue, P.T.; Kawai, K.; Chailapakul, O.; Takamura, Y. Electrochemical Immunoassay Using Open Circuit Potential Detection Labeled by Platinum Nanoparticles. Sensors 2018, 18, 444.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map

1
Back to TopTop