Quantitative Diffractometric Biosensing
Yves Blickenstorfer, Markus Müller, Roland Dreyfus, Andreas Michael Reichmuth, Christof Fattinger, Andreas Frutiger
Abstract
Label-free optical biosensors are an invaluable tool for drug discovery. Refractometric biosensors (the current gold standard) are sensitive and quantitative, yet due to their integrative nature are also extremely cross-sensitive to temperature and nonspecific binding. $D\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}f\phantom{\rule{0}{0ex}}f\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c$ biosensors, however, can reject these environmental noise sources via spatial lock-in of the binding signal, while remaining just as sensitive. Quantification of the biomolecular mass bound to a diffractometric sensor has remained elusive for most optical arrangements, but this study closes the gap by providing a unified theoretical framework for all two-dimensional diffractometric biosensors.