Amplified telomerase analysis by using rotating magnetic particles: The rapid and sensitive detection of cancer cells

A highly sensitive telomerase detection method that involves amplified telomerase analysis and the use of rotating magnetic particles has been developed. Magnetic particles, functionalized with a primer (1) that is recognized by telomerase, are mixed with a nucleotide mixture that includes biotinylated-dUTP, and telomerase-induced elongation of the primers proceeds with simultaneous biotin incorporation. Avidin-Horseradish peroxidase conjugate, coupled to biotin labels, yields the biocatalytic functional particles. Mixing the resulting particles with naphthoquinone-modified magnetic particles enables the optoelectronic detection of telomerase. Attraction of the magnetic particles to an electrode, followed by rotation of the particles, causes the electrocatalytic reduction of O-2 to H2O2 and HRP-catalyzed oxidation of luminol (3); this results in chemilumunescence. The intensity of the emitted light depends on the telomerase content of the sample and the rotation speed of the particles. A minimum number of 10 cancer cells could be detected.