Sensitive and Bidirectional Detection of Urine Telomerase Based on the Four Detection-Color States of Difunctional Gold Nanoparticle Probe

Telomerase, a valuable biomarker, is highly correlated with the development of most of human cancers. Here, we develop a bidirectional strategy for telomerase activity detection and bladder cancer diagnosis based on four detection-color states of difunctional gold nanoparticle (GNP) probes such as blue, purple, red, and precipitate. Specifically, we define the red GNP probe as origin, which represents urine extracts with inactive telomerase and implies normal individuals. The forward direction is corresponding to the detection of a relatively high concentration of active telomerase, in which system GNP probes assemble obviously and precipitate, predicting bladder cancer samples. The negative direction is corresponding to extracts with a relatively low concentration (purple) and without any telomerase (blue), which can be differentiated by naked eyes or UV–vis spectrum, indicating bladder cancer and normal individuals, respectively. More importantly, this noninvasive strategy shows great sensitivity and selectivity when tested by 18 urine specimens from bladder cancer patients, inflammation, and normal individuals