Microsensor arrays and method of using same for detecting analytes

A method of detecting the presence of an analyte in a sample, comprising:

• providing an electromagnetic radiation generating source having a transparent or translucent protective layer thereon, said protective layer having at least one well formed therein, wherein the bottom of the well does not reach the electromagnetic radiation generating source and wherein a chemical sensor is positioned in the well for reactive contact with the analyte in the sample;
• generating electromagnetic radiation from the source causing the chemical sensor to emit a first spectroscopic signal;
• contacting the chemical sensor with the sample causing the chemical sensor to emit a second spectroscopic signal;
• detecting the first and second spectroscopic signals;
• and
• comparing the first spectroscopic signal to the second spectroscopic signal,
• wherein a difference between the first spectroscopic signal and the second spectroscopic signal indicates the presence of the analyte in the sample.