Final Report: Quantum Dot/Aptamer Real-Time Flow Sensor

EPA Contract Number: EPD10039
Title: Quantum Dot/Aptamer Real-Time Flow Sensor
Investigators: Bogomolova, Anastasia
Small Business: Smart Polymers Research Corporation
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2010 through August 31, 2010
Project Amount: $69,999
RFA: Small Business Innovation Research (SBIR) - Phase I (2010) RFA Text |  Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Homeland Security


The purpose of the Phase I research was to develop a feasible approach to real-time flow sensing of water contamination using aptamer-target recognition principle and quantum dot fluorescent labels. To focus on the method development, two known aptamers and corresponding specific targets were used as pathogen simulants in Phase I. Individual sensing with sensitivity and specificity characterization, as well as exploring the potential for multispecific detection, were part of the Phase I project. The goal of the Phase I effort was to prove the feasibility of Smart Polymers Research Corporation's detection approach, which was successfully achieved.

Summary/Accomplishments (Outputs/Outcomes):

Smart Polymers Research Corporation has successfully developed and optimized a working prototype of a novel real-time fluorescent flow sensor. The sensor utilizes aptamer recognition principle and fluorescent quantum dot labels. The sensor is based on a competitive displacement approach to measure the binding of the analyte, which keeps the nonspecific binding below detectable levels. The sensor can function both in real-time for continuous target detection as well as in discontinuous mode for measurements performed with time intervals. In both modes, the response is concentration-dependent. Smart Polymers Research Corporation has performed significant optimization of the sensing surface preparation to achieve highest sensitivity. Smart Polymers Research Corporation was able to detect biologically relevant concentrations of two chosen targets, ATP and IgE, using specific aptamer recognition. Simultaneous bi-specific detection has been demonstrated successfully. Real-time amplification-free detection using aptamer binding has never been reported before and has a high scientific and commercial potential. The approach will be applied to the detection of real life pathogens in Phase II.


Smart Polymers has successfully completed all 5 tasks of Phase I, obtaining positive and novel results. Smart Polymers has proved the feasibility of its approach for real-time flow sensing and has developed a working sensor prototype using known aptamers and corresponding targets. The success of the Phase I research effort exceeded expectations and will guarantee a functional product by the end of Phase II.

Upon completion of Phase II, Smart Polymers intends to have a fully functional, multispecific, real-time fluorescent flow sensor for detection of several important bio-threat agents in water and in aerosolized form. The sensor will be miniature, economical, and ready-to-use in field conditions. It will possess enhanced specificity (due to the competitive displacement detection principle) and stability (due to the use of DNA aptamers as recognition elements). The sensor will possess flexible (tailored) specificity, which will be designed to meet the most urgent needs by changing the specific aptamer. For detection of aerosolized pathogens, the developed fluorescent flow sensor will be integrated with bio-aerosol-specific air sampler SKC BioSampler (SKC Inc., Eighty Four, PA), designed for sampling airborne particulates of biological origin (e.g., bacteria, fungi, pollen, viruses) and their fragments and by-products. A more powerful BioGuardian® Air Sampler (InnovaTek, Inc., Richland, WA) can be incorporated in the fully automated system.  
During and after Phase II, a big part of the commercialization strategy will be to build strategic alliances with larger, well-established environmental/indoor air- and water-monitoring equipment producing companies by out-licensing Smart Polymers' core aptamer-based fluorescence detection technology. Smart Polymers plans to create prototypes that will be used to attract attention of larger companies that are active in the air quality control and drinking water monitoring market and in the position to potentially license and co-market the fluorescence sensor. To maximize the possibility of transfer of its technology to the market place, Smart Polymers already has obtained commitments from two companies to assist us in the design, construction, and marketing of the proposed devices. One is Ultrafast Systems, LLC (Sarasota, FL), which specializes in detecting and processing optical signals in chemical and biological systems, optical engineering, and software design, and Pure Air Control Services (Clearwater, FL), which specializes in building and HVAC system monitoring, diagnostics, and remediation. The most likely source of revenue from the technology developed in Phase II will come from upfront and royalty payments upon licensing the sensor technology to a larger manufacturer that has active marketing channels into bio-weapon detection markets.
The proposed fluorescent sensor can have a wide range of commercial applications due to the versatility and adaptability of the underlying technology. The immediate applications can be broadly defined as targeted toward:  1) military, 2) first responders, and 3) the civilian sector. Based on mission requirements and the possibility of battlefield contamination, the military is expected to remain the largest consumer. Second are civil defense and law enforcement agencies, or first responders. These end-users are present at state and local levels and are tasked with protecting civilians in the event of a weopon of mass destruction (WMD) attack. The third group of end-users is found in the civilian sector. These are primarily companies involved in chemical and biological demilitarization work and government agencies without first responder duties.

Supplemental Keywords:

small business, SBIR, EPA, aptamer, quantum dot, fluorescence, fluorescent quantum dots, pathogens, biothreat, environmental monitoring, sensor, biowarfare agents, water monitoring, air monitoring, homeland security, real-time monitoring, biological pathogens, fluorescence wavelength, food pathogens, public health, bioterrorism, pathogen detection

SBIR Phase II:

Quantum Dot/Aptamer Real-Time Flow Sensor