Nanoparticle Detection with Portable and Low-Cost Lensless Holographic Microscopy Platform

In the biological and medical science, detection of biomolecule at very low concentration (<100 pg/mL) is of great importance and it is extensively used in the diagnosis of diseases, drug response monitoring and cancer research. For biomolecule detection tests, captured biomolecules generate signals (fluorescence, color, etc.), which are analyzed by trained personnel in bulky, high cost and fragile devices. However, for clinical applications, the access to these tests is very difficult at resourcelimited settings. Lensless holographic microscopy provides high resolution imaging of samples without the need of expensive and fragile optical elements (mirror, lens, filter, etc.) used in traditional imaging technologies. While this technology offers a robust, portable and low-cost design, it enables fully automated processing of the sample image with digital processing schemes and this can also help eliminate user error. In this study, lensless holographic microscopy platform, which can be used in surface coverage assays for the detection of biomolecules, is proposed. It has been shown that nanoparticles (700-1200 nm) used as labels in surface coverage assays for the detection of biomolecules could be sensed on the platform. Therefore, it is anticipated that biomolecules detection could be realized rapidly and sensitively with this easy-to-use and low-cost imaging platform at the location where the high-level health institutions are not available and even at point-of-care settings.