Multipurpose analysis using second harmonic generating nanoprobes

A second harmonic generating (SHG) nanoprobe system for nucleotide sequencing comprising:

• a plurality of distinct SHG nanoprobes, each of said distinct SHG nanoprobes having no inversion symmetry, the number of such distinct SHG nanoprobes being sufficient such that each distinct nucleotide type to be sequenced has a distinct SHG nanoprobe assigned thereto;
• and
• an external excitation source for sequentially radiating each of a plurality of nucleotides to be sequenced over at least two distinct excitation wavelengths, wherein the SHG nanoprobes are selected such that the radiation generated by each of the SHG nanoprobes when said nanoprobes are excited at the at least two excitation wavelengths by the external excitation source creates an intensity ratio unique to each said distinct SHG nanoprobe when measured over at least two distinct emission wavelengths;
• a detector configured to detect the sequential emissions of the plurality of distinct SHG nanoprobes at the at least Iwo distinct emission wavelengths;
• and
• an analyzer for comparing the measured intensities from the sequential emissions at the at least two distinct emission wavelengths to determine a measured intensity ratio, and comparing said measured intensity ratio against a known standard for each of the distinct SHG nanoprobes, thereby sequentially determining each nucleotide in a target sequence.