Significant improvements in cancer survival rates are expected with the development of increasingly sensitive and rapid early detection methods and the ability to detect biomarkers of disease. Mounting evidence has implicated microRNA (miRNA) expression profiles as potential cancer biomarkers because aberrant miRNA expression profiles have been linked to the development of several cancer types. Unfortunately, conventional miRNA detection technologies such as microarray analysis and quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR), while can serve as adequate research tools, require expensive reagents, instrumentation, and multiple time-consuming steps and therefore are not suited for routine miRNA based diagnostic testing. This project is aimed to develop a new platform technology based on surface-enhanced Raman spectroscopy (SERS) for profiling of miRNA expression. This label-free detection method offers a tremendous advantage over conventional miRNA detection methods by eliminating issues associated with species-specific reagents, the need for amplification of the analyte for detection, decreasing expense and complicated procedures that are associated with labelling steps. Central to this technology is a nanofabrication method, oblique angle deposition, recently developed in our laboratory to reproducibly fabricate uniform silver nanorod arrays in large area that dramatically enhance the Raman signal of the molecular signature of the analyte. Preliminary data have been obtained to establish the sensitivity and reproducibility of silver nanorod array SERS substrates and demonstrate rapid (less than 10 second), multiplexed (five different miRNAs) detection and quantization of synthetic miRNA mixtures adsorbed directly (i.e., no hybridization or capture) onto the SERS substrates. In order to achieve the high specificity, high sensitivity, and high throughput detections, this project will optimize the hybridization process of SERS chip to improve sensor?s specificity and sensitivity, as well as to serve a means of concentrating the miRNAs, to develop microarray SERS chip for high sensitive, high specificity and high throughput miRNA detection and multiplexing, to integrate microfluidic SERS chip with electric field concentration to reduce hybridization time and maximize hybridization efficiency and to improve the quality of the quantitative detection, and to demonstrate that the technology can detect and quantify miRNA isolated from cells.
Broader Impacts
This project represents an innovative and comprehensive approach toward developing a platform enabling technology to allow for rapid and sensitive detection of miRNA and miRNA expression profiles. miRNAs are recognized as potential biomarkers of disease, thus a novel sensor platform which advances the ability to detect miRNAs would have unusually high impact on biomedical research by providing the ability to improve our fundamental understanding of miRNAs in gene regulation and in disease pathogenesis. Moreover, a new detection platform would dramatically improve miRNA detection, risk assessment, and treatment and monitoring of patients. These features would provide a new paradigm in RNA biology and offer a translational approach to personal care medicine.
A unique educational aspect of this project is the potential to cross-train graduate and undergraduate students in these different scientific disciplines of nanofabrication, spectroscopy and virology. The development of novel viral biosensors provides a mechanism to bridge basic and biomedical research areas, and serves as a unique training vehicle for chemistry, physics and veterinary scientists with interests in viral diseases. In particular, SERS-based biosensors will be used to train a new generation of veterinarians in the College of Veterinary Medicine at University of Georgia to detect infectious diseases using emerging nanotechnology methods.
