DNA Diagnostics: Nanotechnology-Enhanced Electrochemical Detection of Nucleic Acids

Abstract

ABSTRACT:The detection of mismatched base pairs in DNA plays a crucial role in the diagnosis of genetic-related diseases and conditions, especially for early stage treatment. Among the various biosensors that have been used for DNA detection, EC sensors show great promise because they are capable of precise DNA recognition and efficient signal transduction. Advancements in micro-and nanotechnologies, specifically fabrication techniques and new nanomaterials, have enabled for the development of highly sensitive, highly specific sensors making them attractive for the detection of small sequence variations. Furthermore, the integration of sensors with sample preparation and fluidic processes enables for rapid, multiplexed DNA detection essential for POC clinical diagnostics. T he recent discovery and sequencing of the human genome has provided valuable insight into understanding how genetic factors contribute to the development of disease. Specifically, the detection of DNA sequence variations plays an important role in the diagnosis of genetic-related diseases and conditions, especially for early stage treatment and monitoring. Among the different types of diseases caused by DNA alterations, sequence-specific mismatch has the most importance, yet is extremely difficult to detect (1), especially for single-nucleotide polymorphism (SNP). Furthermore, sequence-specific detection has great importance in various medical and scientific applications such as the diagnosis of inherited diseases and the study of pathogen response and bacterial/viral detection.Because of the complex nature of DNA, the detection of single or small numbers of base mismatches requires high sensitivity and specificity (2-4). Current detection methods rely on sample amplification combined with meticulous experimental stringency control (5). For example, polymerase chain reaction (PCR) requires careful primer design and accurate temperature control to obtain sensitivities in the fM range with single-base mismatch specificity (1,3,4). Although these conventional technologies provide the golden standard for laboratory-based DNA diagnostics, they cannot meet the requirements of POC clinical diagnostics (4).EC sensors, initially developed to detect biomolecules in a laboratory setting, have recently found extensive applications for on-site biosensing and detection (6,7), especially for medical and clinical diagnostics (8 -12). While offering simplicity in operation and sample manipulation, the contemporary EC biosensor also provides highly sensitive and specific measurements for a broad spectrum of biomolecules (13-17). The sample size required for current EC sensors is small, ranging from several microliters to hundreds of nanoliters, which includes the sample pretreatment reagents. Additionally, the detection time is relatively fast, varying from a few minutes to tens of seconds. However, the most important feature of EC sensors is their potential to be easily transformed from a laboratory-based instrument to a commercializable POC device. Because o...

Toward Non-Enzymatic Ultrasensitive Identification of Single Nucleotide Polymorphisms by Optical Methods

“…Amplified DNA targets can be analyzed for the presence of SNP by different direct and indirect hybridization strategies including intercalator dyes in allele-specific digital PCR (dPCR) [17], sequence-specific fluorogenic probes [18], electrochemical sensors [19][20][21][22][23][24] and diagnostic nano-materials [25]. Electrochemical sensing is a promising approach for SNP detection which takes advantage of synthetic oligonucleotide probes and the large thermodynamic changes in enthalpy and entropy.…”

“…nano-particles and fluorescence spectroscopy [17][18][19][20][21][22][23][24][25]. Next several efficient colorimetric assays for SNP sensing in amplified DNA have been developed based on modified gold nano-particles (Au-nps; Figure 2) [26].…”

Enzyme-Free Amplification by Nano Sticky Balls for Visual Detection of ssDNA/RNA Oligonucleotides

“…Visual detections of nucleic acids provide simple and rapid assays with visualized readout 1 , and have been widely used for pathogen identification [2][3][4][5] or disease diagnosis [6][7][8] . Nanomaterials, such as gold nanoparticles (AuNPs) 9-14 , silver nanoparticles 15 and graphene oxide 16 , have been employed for the visual detections according to their unique optical properties, biocompatibility, conductivity, and high surface-to-volume ratio [17][18][19][20][21][22] .…”

Diagnosis of Sugarcane White Leaf Disease Using the Highly Sensitive DNA Based Voltammetric Electrochemical Determination

“…Currently, the advances in nucleic acid recognition and a discovery of its electrochemical activity have contributed to an exciting progress in DNA behavior investigation and construction of its hybridization probe sensor as a new strategy for greater detection capability than conventional methods. Particularly the determination using electrochemical methods has attracted much interest because of their simple instrumentation, high specificity, sensitivity, speedy, and is inexpensive with potential for applications in molecular sensing devices [13]- [15].…”