Patent ID: 8642527

Claim:
An aqueous solution for substrate cleaning comprising: a. about 0.001 to about 10% by weight of the aqueous solution of a source of oxidant, wherein said oxidant is sodium hypochlorite; b. about 0.0001 to about 5% by weight percent of the aqueous solution of a plurality of optically functional nanoparticles characterized such that i. the average density of the plurality of optically functional nanoparticles is greater than that of the aqueous solution with the source of oxidant present, and; ii. the average particle size of the plurality of optically functional nanoparticles is between 0.1 nanometers to about 400 nanometers; wherein said composition is concentrated and colored; and c. optionally, an oxidant-stable polymer; d. optionally, an oxidant-stable surfactant; and e. water; wherein the plurality of optically functional nanoparticles are visibly colored particles exhibiting at least one optical absorbance hand providing a human perceivable color to the aqueous solution that lies within the visible spectrum of about 300 to about 800 nanometers wavelength; and wherein said plurality of optically functional nanoparticles are semiconductor quantum dots.