TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Oxide: The metal oxide is titania, zinc oxide, silica, tin dioxide, tungsten trioxide, tantalum trioxide, barium titanate, barium zirconate, zirconium dioxide, hafnium dioxide, alumina, yttrium trioxide, zirconium silicate, ferric trioxide, magnetite, cerium oxide and/or chromium trioxide. Preferred Compound: The nano crystal is metal, group II-VI compound, group II-V compound, group III-VI compound, group III-VI compound, group IV-VI compound, group I-VI compound, group II-IV-VI compound and/or group II-IV-V compound. Preferred Process: The nano crystal is formed of material chosen from cadmium sulfide, cadmium selenium, cadmium terbium, zinc sulfide, zinc selenium, mercury sulfide, mercury selenium, mercury terbium, gallium nitride, gallium phosphite, gallium arsenic, indium phosphite, indium arsenic, indium antimony, aluminum antimony, aluminum phosphate, aluminum arsenic, aluminum antimony, silicon carbide, iron, platinum, nickel, cobalt, aluminum, silver, gold, copper, iron platinum, palladium, silicon, germanium, lead sulfide, lead selenium and/or lead terbium. Preferred Structure: The nano crystal is core-shell structure.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Agent: The surfactant is hydrophilic surfactant of formula: An-(Rn)-Bl (1), and alkyl amine surfactant chosen from monomethyl amine, dimethyl amine, trimethyl amine, monoethyl amine, diethyl amine, triethyl amine, isopropyl amine, diisopropyl amine, mono-n-propyl amine, di-n-propyl amine, tri-n-propyl amine, mono-n-butyl amine, di-n-butyl amine, tri-n-butyl amine, mono-sec-butyl amine, di-sec-butyl amine, tri-sec-butyl amine, mono-tert-butyl amine, di-tert-butyl amine, cyclohexyl amine, dicyclohexyl amine, octyl amine, dodecyl amine, hexadecyl amine, dimethylaminoethyl amine, N-ethyl ethylene diamine or N,N-dimethyl-1,3-propane diamine.A=thio, amino, carboxylic acid, phosphonic acid, phosphine oxide, nitrile or thiocyanate;B=hydroxyl, carboxylic acid, amino, phosphonic, or sulfonic acid;R=hydrocarbon, polyether, ethylene or propylene;n,l=1-4;andm=1-22.