Label-Free Detection of E. coli O157:H7 DNA Using Light-Addressable Potentiometric Sensors with Highly Oriented ZnO Nanorod Arrays

Abstract

The detection of bacterial deoxyribonucleic acid (DNA) is of great significance in the quality control of food and water. In this study, a light-addressable potentiometric sensor (LAPS) deposited with highly oriented ZnO nanorod arrays (NRAs) was used for the label-free detection of single-stranded bacterial DNA (ssDNA). A functional, sensitive surface for the detection of Escherichia coli (E. coli) O157:H7 DNA was prepared by the covalent immobilization of the specific probe single-stranded DNA (ssDNA) on the LAPS surface. The functional surface was exposed to solutions containing the target E. coli ssDNA molecules, which allowed for the hybridization of the target ssDNA with the probe ssDNA. The surface charge changes induced by the hybridization of the probe ssDNA with the target E. coli ssDNA were monitored using LAPS measurements in a label-free manner. The results indicate that distinct signal changes can be registered and recorded to detect the target E. coli ssDNA. The lower detection limit of the target ssDNA corresponded to 1.0 × 10 2 colony forming units (CFUs)/mL of E. coli O157:H7 cells. All the results demonstrate that this DNA biosensor, based on the electrostatic detection of ssDNA, provides a novel approach for the sensitive and effective detection of bacterial DNA, which has promising prospects and potential applications in the quality control of food and water.

Nanomaterials in the Management of Gram-Negative Bacterial Infections

“…The schematic construction of a ZnO/GaAs BAW nanosensor for identification of E. coli is depicted in Figure 8. [97]. The recognition element for specific detection of E. coli O157:H7 DNA was constructed by attachment of ssDNA on the surface of LAPS.…”

“…Reprinted from Ref. [105].Tian et al developed a label-free nanosensor based on the light-addressable potentiometric sensor (LAPS) and ssDNA-ZnO nanorod arrays (NRAs)[97]. The recognition element for specific detection of E. coli O157:H7 DNA was constructed by attachment of ssDNA on the surface of LAPS.…”

Amphiphilic Conjugated Polythiophene‐based Fluorescence “Turn on” Sensor for Selective Detection of Escherichia coli in Water and Milk

“…In particular, many researchers are developing labelfree detection methods to reduce the time consumed by the labeling process, which generally takes more than 1 day after incubation. [13][14][15][16] Over the years, various bacteria detection methods, for instances, optical 17,18 photoelectrochemical 19 and electrochemical impedance spectroscopy 20 have been established to overcome the practical difficulties of traditional methods. Conversely, these aforementioned detection methods have low selectivity, require expensive antibodies, and tedious labor, which restricts their widespread use in practical applications.…”

“…Despite much research being devoted to the detection of E. coli , it still has disadvantages such as costly, time‐consuming, culturing methods, and colony counting. In particular, many researchers are developing label‐free detection methods to reduce the time consumed by the labeling process, which generally takes more than 1 day after incubation 13–16 …”

Light-Addressable Potentiometric Sensors in Microfluidics

“…Therefore, various biochemical reactions such as enzymatic reaction, redox reaction, antigen-antibody specific reaction, etc., could potentially be detected by LAPS. At present, LAPS has broad application prospects in the fields of pH detection [4] , ion detection [5][6] , molecular detection [7][8] , enzymatic reaction [9] , cell metabolism [10][11][12][13][14] , immunoassay and DNA detection [15][16][17] .…”