Abstract: A process for detecting nucleic acids, having the following steps: providing at least one nanoparticle that is functionalised for the nucleic acid to be detected by means of at least one oligonucleotide that is bound to it and that is able to hybridize with at least one segment of a nucleic acid to be detected; bringing the functionalised nanoparticle into contact with a sample in which the nucleic acid is to be detected; and measuring a property that provides information about the degree of hybridization of the at least one oligonucleotide with the nucleic acid to be detected. In addition, the process includes the step of exciting the nanoparticles to generate heat, for example by means of a photothermal effect. The invention is suitable, in particular, for high-throughput DNA analysis.

Abstract: The present invention provides cobalamin acid hydrazides of the general formula:B--CO--NH--NH--R--CO--NH--NH).sub.x H (I)wherein B is a residue formed from a cobalamin by the splitting off of a --CONH.sub.2 group, R is a spacer and x is 0 or 1, as well as a process for the preparation thereof.The present invention also provides cobalamin conjugates of the general formula:B--d--CO--NH--NH--R--CO--NH).sub.x N.dbd.GP (II)in which B, R and x have the above-given meanings and d signifies the position of --CO--NH--, as well as a process for the preparation thereof. These cobalamin conjugates are very suitable for use in immunoassays, especially for the determination of cyanocobalamin.