An innovative blood testing technique has been described in the most recent issue of Biomedical Optics Express. Researchers from the University of Toledo in Ohio have developed an inexpensive, fast and portable technique to detect concentrations of certain molecules in blood.
This new technique makes use of aptamers. Aptamers are artificial short-strands of nucleic acid able to serve as antibody mimics due to high affinity and selectivity for various target molecules. The research team engineered a sensor with aptamers on its gold coated surface. On presentation of the blood sample on the sensor surface, the aptamer and the specific protein would stick together. Thrombin and thrombin-binding aptamers were used in this research model. Using Surface Plasmon Resonance (SPR), which is a real-time spectroscopic technique based on wave-motions of electrons placed on a sensor surface, the researchers were able to detect the resonance change caused by the binding of the protein with the aptamer. Changes in resonance can then be translated into the amount of the target protein.
Though only thrombin and thrombin-binding aptamers were demonstrated, unique aptamers for almost any given protein can be identified. Aptamer sensors can also release the target molecules, making them perfect receptors for biosensing applications, the researchers stated. Advantages of this new method are its size, speed, sensitivity and its low sample consumption.
For the future, the researchers plan to optimize the sensor’s performance by optimizing the concentration of aptamers on the sensor surface. Furthermore they are in the process of identifying the specific aptamers for different blood proteins. Brent D. Cameron, one of the authors, mentioned that the technology is three to five years away from commercial use in medical diagnostics.