Functionalized paper microzone plate for colorimetry and up-conversion fluorescence dual-mode detection of telomerase based on elongation and capturing amplification

As an important cancer biomarker and therapeutic target, telomerase has attracted special attention especially concerning its detection and monitoring. Here, we established a portable cellulose paper substrate for the detection of telomerase based on colorimetry and up-conversion fluorescence dual-mode methods The sterile cellulose paper substrate functionalized with telomerase substrate oligonucleotide were used as the capturing substrate, on which the telomerase extended telomeric repeats, and the corresponding telomeric repeat complementary oligonucleotide labelled with methylene blue or the up-conversion nanoparticles (UCNPs) were employed as the colorimetric or up-conversion fluorescence reporting nanolabels. The extended telomeric repeats subsequently facilitate capturing of the more reporting nanolabels via hybridization between telomeric repeat and its complementary oligonucleotide, inducing a significant amplified signal in the color and up-conversion intensity. Colorimetric functionality allows rapid preliminary discrimination of telomerase activity by the naked eye, and the low background up-conversion fluorescence increases the sensitivity of this method. Moreover, the developed cellulose paper device is more stable and easily stores the tests results compared with majority solution-phase systems.