Abstract: A method for photoplethysmography measurement couples a color camera in optical contact against a skin surface of a subject and couples at least a first solid-state illumination source in optical contact against the skin surface, wherein the first solid-state illumination source has a first wavelength range with a first bandwidth that exceeds 50 nm. The illumination source and color camera are energized over a predetermined time interval to acquire a first sequence of image frames from the skin surface. A set of hue values is computed from each of the acquired sequence of image frames and photoplethysmography data generated according to periodic changes in an average hue per frame computation. The generated photoplethysmography data is presented on a display.

Abstract: The invention relates to a sensor molecule for detecting a target molecule comprising: (a) a rod-like molecule L and a rod-like molecule R connected to each other by a joint molecule C to form a hinge; (b) a target binding molecule A bonded to the end of rod-like molecule L opposite to the joint molecule C; (c) a binding molecule A? bonded to the end of rod-like molecule R opposite the joint molecule C; wherein the target binding molecule A is arranged to bind to the target molecule to be detected, and binding molecule A? is arranged to bind to: i) the same target molecule as target binding molecule A; or ii) a complex of the target binding molecule A and the target; and wherein the hinge is biased into an open position, such that target binding molecule A and binding molecule A? are biased apart by the hinge.