SBIR-STTR Award

The research described in this proposal details a procedure for detecting and quantifying Illicit Drugs using an immunoassay coupled with surface enhanced Raman scattering (SERS) spectroscopy. The technique has the advantage of high sensitivity due to the use of SERS. In addition, the unique surface sensitive detection of SERS means that the assay can be read without washing away the indicator antigens. This makes it possible to easily automate this method for rapid screening of large numbers of samples in a microwell plate format. The assays will be demonstrated with microwell plates that have been modified with a SERS active colloid. The SERS surface will be treated with anti-illicit drug, dye-tagged drugs, and processed to form a pretreated plate. These will represent part of the commercial product to be developed and will be tested for durability. The analysis will be performed by sample introduction onto the modified microwell plate. Only those drugs that are captured and displace the reporter conjugates on the surface will produce SERS spectra from the microtiter wells. Dye drug conjugates that are not captured are not observed as their spectra are not enhanced by the SERS effect. We will investigate several dye conjugates that have absorptions in the red to enhance the sensitivity of our technique. We will use both a 633 nm HeNe laser system for the analysis. Tests will be made with whole blood, saliva, and perspiration. PROPOSED COMMERCIAL APPLICATION Current methods for immunoassay are difficult, time consuming, and require hazardous radioactive reagents. The washing step that we eliminate makes automation difficult in current methods since most samples requires strengent washing to remove the tagged drugs. The technique proposed here will provide a quantitative result without washing and will be very easily automated for large scale rapid analysis. We are proposing to look at illicit drug analysis, however, the methodology can be adapted to all immunoassays.

The goal of the proposed research is to develop two prototype drug analyzers interfaced with automated analysis readers for low risk monitoring of illicit drug levels by Surface Enhanced Raman Immuno Assay (SERIA). The first prototype will be placed in a clinical setting. This study will include urine and saliva samples collected from clients of a juvenile assessment and treatment center. We will cross validate this work with a comparison to conventional immunoassay measurements through standard urinalysis methodology. This will provide us with a credible validation and a beginning for FDA approval.The second prototype drug analyzer will be developed as a multiformat instrument and optimized to evaluate the engineering and automated assay methodology. This instrument will be designed to accommodate a microwell plate format for screening drug samples, a microsample vial format for individual drug assays, and a simple one-step test-strip format.In the course of this project we will further the development of our assay technique by improving upon the design of our drug-analog reporters and optimizing our methodology for the detection of methamphetamine, amphetamine, and morphine by extending our study to include THC and cocaine, and developing corresponding SERIA methods for these drugs