The outputs of molecular sensors detectable by human senses

Molecular sensors respond to the presence of biological analytes by producing signals that are either directly perceivable by human sensory systems or converted into electric signals, which require electronic devices for communicating the signals to humans. Here, we review the outputs of molecular sensors detectable directly by human senses. According to the literature, sensors with visual outputs dominate. Undeservedly unnoticed, sensors that release gases might be particularly useful since the gas output can be detected with the several human senses in a quantifiable format. Relatively new sensors with tactile outputs can be accessed by visually impaired people. Molecular sensors communicating their outputs directly to human senses bypassing electronic devices may contribute to the development of point-of-care testing technologies, as well as providing the direct communication of molecular nanorobots with humans.