Modified oligonucleotides comprising thiol functions and use thereof for detecting nucleic acids

Modified oligonucleotide corresponding to the formula:

• in which,
• n is an integer ranging from 4 to 100,
• y is an integer ranging from 2 to 12,
• N1, . . . , Nn represent, independently of one another, a nucleotide,
• X is selected from linear or branched C1-C12 alkyl groups, C1-C12 aminoalkyl groups, C1-C12 alkoxy groups, C3-C12 cycloalkyl groups, oxygen-containing or nitrogen-containing C3-C12 cycloheteroalkyl groups,
• Y is selected from linear or branched C1-C12 alkyl groups, C1-C12 aminoalkyl groups, C1-C12 alkoxy groups, C3-C12 cycloalkyl groups, oxygen-containing or nitrogen-containing C3-C12 cycloheteroalkyl groups,
• Z is selected from C1-C12 alkoxy groups, oxygen-containing or nitrogen-containing C3-C12 cycloheteroalkyl groups, C1-C12 NCO-alkyl groups, C1-C12 CON-alkyl groups,
• W is selected from C1-C12 alkane triyl groups, C6-C18 aryl triyl groups and C6-C18 aralkane triyl groups,
• R is H or is selected from C1-C12 acyl, C1-C12 S-alkyl, C6-C12 S-aryl, S-2-pyridine, oxygen-containing or nitrogen-containing C1-C12 S-heteroalkyl, C3-C12 S-cycloalkyl, oxygen-containing or nitrogen-containing C3-C12 S-cycloheteroalkyl groups, and
• Bn represents the base of the n-th nucleotide.