Optical sensor with luminescent quantum nanoprobes

An optical sensor system, comprising:

• a sample;
• a sample holder, configured to hold the sample, in operation, the sample holder comprising a first electrode, a second electrode, and an electrical circuit, the electrical circuit being coupled to the first and second electrodes, the first electrode being positioned to the sample and the second electrode being positioned to the sample;
• a probe, comprising an arrangement of quantum dot material, the quantum dot material selected from the group consisting of II-VI elements and III-V elements, the quantum dot material forming luminescent quantum dots, wherein the probe is positioned vertically above the sample, the probe being positioned and vertically moveable, in a direction substantially perpendicular to the sample holder, to be in physical contact with the sample and out of physical contact with the sample, the sample held by the sample holder not being the luminescent quantum dots, a bottom surface of the probe containing the quantum dot material being substantially parallel to the sample holder;
• an optical source, configured to optically excite the luminescent quantum dots;
• a lens positioned between the probe and the optical source, the lens being separated from the probe such that the lens is free from being directly attached to the probe;
• an optical detector, configured to read optical signals from the luminescent quantum dots, such that the lens is positioned between the optical detector and the luminescent quantum dots;
• and
• another circuit connected to the optical detector and configured to determine correlations between the optical signals read by the optical detector;
• wherein, the probe is positionable relative to the sample, such that the optical signals from each of the luminescent quantum dots are influenced by the sample, in operation;
• and
• wherein the luminescent quantum dots are arranged in multiple sets of three quantum dots in the probe, each of the sets of the three quantum dots comprising a first one of the three quantum dots having a first size, a second one of the three quantum dots having a second size different from the first size, and a third one of the three quantum dots having a third size different from the first and second sizes, each of the first one, the second one, and the third one of the three quantum dots being essentially arranged in a same plane in the probe.