An air conditioning module is constructed to include all the necessary components for an air conditioning system within a single housing, with the housing having a supply air opening and a return air opening. The mechanism measures the fluctuations of the optical property of the volume of interest for determining the position of the volume of interest. A surface modification method comprising bringing, into a high-temperature flame formed by use of a combustible gas and a combustion-supporting gas, the inorganic oxide powder A; and bringing again the resultant powder into the high-temperature flame, to thereby modify the surfaces of particles of powder A. This enables the upper surface of the junction block to be covered for a water-entrance preventing purpose, and can prevent such an operation from being forgotten. Colloidal nanoparticle is characterized by an inorganic surface having attached to it one or more of the ligands, The colloidal bioconjugate is characterized by an inorganic surface having attached thereto one or more of the ligand wherein at least some of the ligand have a biomolecule conjugated thereto.