1. Parallel optical read-out of micromechanical pillars applied to prostate specific membrane antigen detection
- Author
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Martina Tardivo, Sergio Carrato, Giulio Fracasso, Daniele Borin, Andrea Colusso, Moreno Meneghetti, Marco Lazzarino, Giacinto Scoles, Marco Colombatti, Valeria Toffoli, Simone Dal Zilio, Tardivo, Martina, Toffoli, Valeria, Fracasso, Giulio, Borin, Daniele, Dal Zilio, Simone, Colusso, Andrea, Carrato, Sergio, Scoles, Giacinto, Meneghetti, Moreno, Colombatti, Marco, and Lazzarino, Marco
- Subjects
Male ,Analyte ,Materials science ,Biomedical Engineering ,Biophysics ,Frequency shift ,Nanotechnology ,Biosensing Techniques ,Tracking (particle physics) ,Buffer (optical fiber) ,parallel optical read-out detection ,Resonator ,Limit of Detection ,Biomarkers, Tumor ,PSMA ,Electrochemistry ,Glutamate carboxypeptidase II ,Humans ,Micromechanical sensors ,Parallel optical read-out detection ,Prostate specific membrane antigen ,Biotechnology ,Micromechanical sensors Parallel optical read-out detection Prostate Specific Membrane Antigen ,Prostate ,Prostatic Neoplasms ,Equipment Design ,General Medicine ,Micro-Electrical-Mechanical Systems ,Prostate-Specific Antigen ,biosensors ,prostate cancer ,Prostate Specific Membrane Antigen ,Antibodies, Immobilized ,Biosensor ,Sensitivity (electronics) ,Biomedical engineering - Abstract
Micro and nanomechanical resonators represent a promising platform for proteins label-free detection because of their extreme sensitivity, fast response and low cost. Micro-pillars are columnar resonators that can be easily arranged in dense arrays of several thousand sensors in a squared mm. To exploit such a large density, however, a method for tracking independently micropillars resonance frequency is required. Here we present a detection method based on CCD imaging and software image analysis, which can measure the resonance frequency of tens of pillars in parallel. Acquiring simultaneously the frequency shift of up to 40 sensors and applying a proper statistical analysis, we were able to overcome the variability of the single measures improving the device sensitivity at low analyte concentration range. As a proof of concept, this method has been tested for the detection of a tumor marker, the Prostate Specific Membrane Antigen (PSMA). Pillars have been functionalized with an antibody against PSMA. The tumor marker (PSMA) has been detected in a range of concentrations between 300 pM and 100 nM, in buffer and in diluted bovine serum. The sensitivity of our method was limited only by the affinity constant of the antigen–antibody recognition. Moreover, this detection technique demonstrated to be effective in the 1–6 nM range, which is the window of PSMA concentration of clinical interest.
- Published
- 2015