Optical computing devices may include capacitance-based nanomaterial detectors. For example, an optical computing device may include a light source that emits electromagnetic radiation into an optical train extending from the light source to a capacitance-based nanomaterial detector; a material positioned in the optical train to optically interact with the electromagnetic radiation and produce optically interacted light; and the capacitance-based nanomaterial detector comprising one or more nano-sized materials configured to have a resonantly-tuned absorption spectrum and being configured to receive the optically interacted light, apply a vector related to the characteristic of interest to the optically interacted light using the resonantly-tuned absorption spectrum, and generate an output signal indicative of the characteristic of interest.