Pyrophosphate-Enhanced Oxidase Activity of Cerium Oxide Nanoparticles for Colorimetric Detection of Nucleic Acids.

Seokhwan Kim,Ki Soo Park,Yong-Keun Choi,Ayemeh Bagheri Hashkavayi,Yu Zhou,Heeseok Chung,Jinjoo Han

doi:10.3390/s21227567

Seokhwan Kim, Ki Soo Park + Show 5 more

Open Access

https://doi.org/10.3390/s21227567

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Abstract

In recent years, cerium oxide (CeO2) nanoparticles (NPs) have drawn significant attention owing to their intrinsic enzyme mimetic properties, which make them powerful tools for biomolecular detection. In this work, we evaluated the effect of pyrophosphate (PPi) on the oxidase activity of CeO2 NPs. The presence of PPi was found to enhance the oxidase activity of CeO2 NPs, with enhanced colorimetric signals. This particular effect was then used for the colorimetric detection of target nucleic acids. Overall, the PPi-enhanced colorimetric signals of CeO2 NPs oxidase activity were suppressed by the presence of the target nucleic acids. Compared with previous studies using CeO2 NPs only, our proposed system significantly improved the signal change (ca. 200%), leading to more sensitive and reproducible colorimetric analysis of target nucleic acids. As a proof-of-concept study, the proposed system was successfully applied to the highly selective and sensitive detection of polymerase chain reaction products derived from Klebsiella pneumoniae. Our findings will benefit the rapid detection of nucleic acid biomarkers (e.g., pathogenic bacterial DNA or RNA) in point-of-care settings.

Highlights

Fast, robust, and ultrasensitive detection of target nucleic acids has important applications in molecular diagnostics for the detection of pathogens and viruses [1,2]
The gold standard for the detection of specific nucleic acid involves the exponential amplification of a target DNA fragment using polymerase chain reaction (PCR) followed by gel electrophoresis [3]
We investigated the effect of phosphate ester bonds using different substances, such as Deoxynucleoside triphosphate (dNTPs), ribonucleoside triphosphate (rNTPs), and phosphate ester bonds in phate (PPi), on the oxidase activity of CeO2 NPs during a CeO2 NPscatalyzed oxidation reaction

Summary

Introduction

Robust, and ultrasensitive detection of target nucleic acids has important applications in molecular diagnostics for the detection of pathogens and viruses [1,2]. The gold standard for the detection of specific nucleic acid involves the exponential amplification of a target DNA fragment using polymerase chain reaction (PCR) followed by gel electrophoresis [3]. Real-time PCR, which can amplify DNA in real time, has been widely utilized as a promising alternative [4,5]. Despite its high accuracy, real-time PCR requires expensive reagents (fluorescence-labeled probes or DNA binding dyes) and bulky equipment. These shortcomings become more problematic for point-of-care testing (POCT) applications [6]

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