The objective of this proposal is to develop new modalities for the isolation and detection of selective proteins (biomarkers), by using aptamer-protein interactions in nano/microfluidic channels/chambers with multiplexed nanoscale electrodes and on-chip data processing. To accomplish the goals, a coherent strategy of fabrication and modeling will be adopted: (1) Development of functionalized membranes for isolation of low-abundant disease biomarkers, (2) Design and development of a bio-chip with individually-addressable nano-electrodes, made with high-throughput nanoimprint lithography and functionalized with aptamers for multiplexed detection of biomarkers, (3) Development of novel and rapid fabrication of nano/microfluidic channels, (4) Modeling, analysis and characterization of the electronic properties of biomarker-aptamer interactions measured between the nano-electrodes, and, (5) Real-time low-power noise-free read-out circuit with sequential addressing, actuation, measurement & data analysis of the recognition sites.
INTELLECTUAL MERITS: This proposal will transform and create a new area ?proteonics?, building up on the advances in ?proteomics? and ?molecular electronics?. The activities leverage from the molecular scale devices and the in vitro aptamer-protein interactions, and are extendible to a host of other applications. The ideas will overcome bottlenecks of expensive and serial fabrication in molecular electronics and provide alternate to the labor-intensive, poorly-sensitive and lengthy protocols of proteomics. The novel polymer nano/microfluidics will provide proper conditions to retain protein expression and functionality. On-chip circuit will lead the way to prototype point-of-care proteonic bio-chips. The nano-electrodes will provide a 3-D interaction volume for aptamer-protein binding, resulting in higher sensitivity and signal-to-noise ratio than those for planar morphologies. The approach will also overcome sensitivity limitations by removing the effects of device doping, geometry, dimensions, and fluidic environments. The proposed strategies will innovatively transform and revolutionize a number of disciplines: (1) Rapid nano-manufacturing for bio-sensing, (2) Multiplexed detection of disease markers using various aptamers, (3) Ultrasensitive on-chip electrical detection of biomarkers and analysis for early disease detection, (4) Mask-less production of novel nano/microfluidics.
BROADER IMPACT: The proposal has direct applications in other biosensor domains, e.g. gene expression analysis, virus/pathogen detection and whole blood analysis. The variations of the propose technology can transform biomolecular sensing with better disease intervention strategies, improved statistical confidence and real-time detection. The PI has engaged women graduate students and minority undergraduate/high school students in his research lab. Innovative educational endeavors will be pursued with this proposal: (1) Development of a graduate course on nano-bio devices, (2) Seminars/Demos/Lab-tours focused on research involvement and retention of undergraduates, (3) One-week summer camp for high school students (primarily African-American and Hispanic) from Arlington school district, integrating MEMS/Nano research and biology concepts, (4) Interactive website/blog for the projection/exposure/discussion of the state of the art in research, (5) Saturday morning live-chat sessions to follow-up/engage K-12 students and teachers, (6) Technology transfer studies to nurture entrepreneurship in students interested in real-world problems, (7) Development of international research collaborations for exchange of students from and to USA. The results of the proposed ideas will be disseminated through peer-reviewed articles, conferences and public media.
The objective of this project was to develop new modalities for the isolation and detection of selective proteins (biomarkers), by using aptamer-protein interactions in nano/microfluidic channels/chambers with multiplexed nanoscale electrodes and on-chip data processing. In last five years, many new and exciting discoveries were made. First, functionalized membranes were shown to isolate and enrich low-abundant disease biomarkers (Fig. 1). Next we showed a bio-chip with individually-addressable nano-electrodes could detect these biomarkers at very low concentrations (Fig. 2). We also developed novel and rapid approaches to fabricate nano/microfluidic channels (Fig. 3). We also came across exquisite selectivity between aptamers and tumor cells and have published extensively on surface-grafted aptamers that have shown possibility to isolate tumor cells from sample (Fig. 4). This has been a very transformative work with possible implications in early cancer detection. The early detection of cancer is challenging. Tumors start shedding cancer cells in the blood stream very early in the disease. These cells are called circulating tumor cells (CTC) or rare cells. Their concentration is too low at early stages and thus it is a challenge to detect them. The shedding of CTCs starts way before clinical symptoms of cancer become evident. The work done in the later part of this project focused heavily on developing simple, cheap, rapid and non-invasive tests for cancers that could be done as routine lab-work during annual or biannual physical check-ups. The publications stemming from this project provide many solutions to check for CTCs from blood as well as from simple body fluids like urine, saliva, bladder wash, etc. The outcomes define tests that can be done in a simple clinical setup with minimal intervention need of technicians for analysis or sample handling. During the course of the project, many women students and minority undergraduate/high school students were engaged. Innovative educational endeavors were pursued, e.g. (1) Development of a graduate course on nano-biotechnology, (2) Seminars, demonstrations and lab-tours were given to provide motivation to undergraduates and K-12 students towards STEM fields (Fig. 5), (3) Summer camp presentations were given to high school students, integrating MEMS/Nano research and biology concepts, (4) Interactive fora have been developed using social network for the projection, exposure and discussion of the state of the art in research, (5) Technology transfer studies have been done to nurture entrepreneurship in students interested in real-world problems, (6) International research collaborations have been established.
