UV-light-assisted functionalization of Quartz-Crystal-Microbalance

Photonic Immobilization Technique (PIT) is a novel approach to the functionalization of gold surface that results in antibodies spatially oriented with their variable part side-up. The effectiveness of PIT has been applied to the gold electrode of a Quartz-Crystal-Microbalance (QCM) for the detection of both heavy and light molecules. In the latter case we are able to immobilize the antibody against the parathion (a toxic pesticide with M≈300 Da) setting up a protocol to make the antigen heavier through the complexion with much heavier proteins (Bovine Serum Albumine, BSA). The whole analysis requires 10 minutes and a lower limit of detection (LOD) as low as 4 ppb in water is demonstrated. Given the versatility and robustness of QCM our technique could represent a breakthrough in the realization of easy-to-use, cost effectiveness immunosensors.