Abstract: The present invention provides, in addition to other things, methods, systems, and apparatuses that involve the use of an optical fiber with grating and particulate coating that enables simultaneous heating; optical detection; and optionally temperature measurement. Methods, systems, and apparatuses of the present invention may be used in many applications including isothermal and/or thermal cycling reactions. In certain embodiments, the present invention provides methods, systems, and apparatuses for use in detecting, quantifying and/or identifying one or more known or unknown analytes in a sample.