WEARABLE SWEAT SENSOR

A wearable sweat sensor for detecting one or more analytes in human sweat comprises an optical module comprising at least one light source and at least one light detector; at least one sensor layer optically coupled to the optical module and having optical absorbance properties that are dependent on the concentration of a target analyte of said one or more analytes; and one or more processors in communication with the optical module. The one or more processors are configured to: cause light from the at least one light source to be transmitted towards, and/or through, the at least one sensor layer; obtain, from the at least one light detector, one or more optical signals reflected and/or transmitted from the at least one sensor layer; and determine, from at least one wavelength component of the one or more optical signals, a target analyte concentration.