TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The inorganic shell material comprises NaM2F4, LiMaF4, KM2F4, RbM2F4, CsM2F4, BeM2F5, Be(M2)2F8, MgM2F5, Mg(M2)2F8, CaM2F5, Ca(M2)2F8, SrM2F5, Sr(M2)2F8, BaLnF5, Ba(M))2F8M2F3, M2F3, M2Cl3, M2Br3, M2I3, M2FCIBr, M2OF, M2OCl, M2OBr, M2OS or (M2)2S3 (preferably silica, titania or zinc sulfide).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The polar solvent is water, methanol, ethanol, propyl alcohol, butanol, pentanol, hexanol, ketone, ethylene glycol, glycerol, propylene glycol; polyethylene glycol and/or ethyl acetate. The non-polar solvent is selected from oleylamine, octadecene, oleic acid, alkyl amine, dialkyl amine, trialkyl amine, alkenyl amine, dialkenyl amine, trialkenyl amine, alkyl acid, alkenyl acid, trialkyl phosphine, trialkyl phosphine oxide, trialkylphosphate, alkane, alkene, alkyl ether or alkenyl ether. The compound (I) is selected from CF3COONa or CF3COOLi. The compound (II) is selected from (CF3COO)3Y or (CF3COO)3La. The compound (III) is (CF3COO)2Yb, (CF3COO)3Er, (CF3COO)3Tm or (CF3COO)3Ho. The surfactant has formula R5-(CiHk)(R1)(R2)-( CzHw)y(R3)(R4)-R6. The surfactant is hydrophilic, hydrophobic and/or amphiphilic.j and z=1-9;k, s, w and y=0-9;R1-R5=H, 1-6C alkyl,1-6C aryl (optionally substituted), HS, COOH, NH2 or OH;R6=COOH, NH2, OH, P(O) or P.provided that sum of s and y is less than 10.    TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The treating is carried out in the presence of at least one source of energy such as light source, electric source, thermal source or magnetic source at up to 1000 (preferably 200 - 400, especially 330)degreesC; in the presence of at least one polar and/or non-polar solvent. The method (M1) further involves applying at least one organic and/or inorganic material (shell) on the core, to obtain a core-shell nanoparticle(s). The shell is applied continuously or discontinuously on the core. The surface of the material (M1) is modified by adding at least one surfactant, lipid, polymer and/or inorganic material. The method (M2) involves applying at least one first modifier on the structure surface, and further a second hydrophilic modifier (preferably hydrophilic surfactant) to make a structure-first modifier-second modifier complex. Preparation of the material of formula M1M2Xn:Mq (a2) involves treating (I), (II) and at least one compound of formula (C(X)3(C(X)2)n(CH2)mCOO)pMq (III). Preparation of the material (M2) of formula M2Xn:Mq (a4) involves treating (II) and (III) in the presence of at least one source of energy. The material (a3) is selected from M2F3, M2Cl33, M2Br3, M2I3, M2FClBr, M2OF, M2OCl, M2OBr, M2OS or (M2)2S3 (preferably LaF3, CeF3, GdF3, YF3 or YOF). The material (a4) is M2F3:Mq, M2Cl3:Mq, M2Br3:Mq, M2I3:Mq, M2FClBr:Mq, M2OF:Mq, M2OCl:Mq, M2OBr:Mq, M2OS:Mq or (M2)2S3:Mq.Mq=Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu;andq=0-10.Preferred Material: The material (M1) has hexagonal, cubic, tetragonal, rhombohedral, orthorhombic, monoclinic and/or triclinic (preferably hexagonal) structure. The material (M1) has size less than 50 (preferably less than or equal to10, especially less than or equal to5)nm. The material (M1) in the form nanoparticle(s), nanofilm or monolith. The nanoparticle(s) comprise core nanoparticle(s) and/or core-shell nanoparticle(s) (preferably core nanoparticle). The nanoparticle further comprises at least one organic and/or inorganic material (shell) applied on the core, to obtain a core-shell nanoparticle(s). The shell material comprised compounds (I) or (II). The organic shell material comprises polymer, surfactant and/or lipid. The polymer is selected from polystyrene, polyethylene, polymethyl methacrylate or polylactic acid. A biomolecule is attached to the material (M1). Preferred Components: The nano-structured material (a1) is selected from 15 formulae as given in the specification e.g. NaM2F4, LiM2F4, KM2F4, RbM2F4, CsM2F4, BeM2F5, MgM2F5, CaM2F5, SrM2F5 or Ba(L)nF5 (preferably hexagonal NaYF4); (a2) is selected from 15 formulae as given in the specification e.g. NaM2F4:Mq, LiM2F4:Mq or KM2F4:Mq (preferably NaYF4:Yb). The biomolecule is selected from protein, nucleic acid, nucleosides, nucleotides, DNA, hormone, amino acid, peptide, peptidomimetic, RNA, lipid, albumin, antibody, phospholipids, glycolipid, sterol, vitamins, neurotransmitter, carbohydrate, sugar, disaccharide, monosaccharide, oligopeptide, polypeptide and/or oligosaccharide. The source of excitation is NIR. The NIR is at 980 nm. The unit for is optical fibres, endoscopes, external light or external laser. Preferred Definitions:    M2=Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu.    EXAMPLE - A mixture of sodium trifluoroacetate (1 mmol), trifluoroacetic acid yttrium salt ((CF3COO)3Y) (0.78 mmol), trifluoroacetic acid ytterbium salt ((CF3COO)3Yb) (0.2 mmol) and trifluoroacetic acid erbium ((CF3COO)3Er) (0.2 mmol) was dissolved in butanol and water, and then passed through a 0.22 microns filter to remove any residue. The precursor was dipped onto a glass substrate. A spin-coater was used to spread the precursors on the glass substrate. After drying, it was sintered in an oven at 500degreesC for 10 min to obtain corresponding thin nano-structure material film.