Cancer is rapidly becoming the greatest health hazard of our days. The most widespread cancers, are lung cancer (LC), breast cancer (BC), colorectal cancer (CC), and prostate cancer (PC). The impact of the various techniques used for diagnosis, screening and monitoringthese cancers is either uncertain and/or inconvenient for the patients. This proposal aims to create a low-cost, easy-to-use and noninvasive screening method for LC, BC, CC, and PC based on breath testing with a novel nanosensors approach. With this in mind, we propose to:(a) modify an array of nanosensors based on Au nanoparticles for obtaining highly-sensitive detection levels of breath biomarkers of cancer; and(b) investigate the use of the developed array in a clinical study.Towards this end, we will collect suitable breath samples from patients and healthy controls in a clinical trial and test the feasibility of the device to detect LC, BC, CC, and PC, also in the presence of other diseases.We will then investigate possible ways to identify the stage of the disease, monitor the response to cancertreatment, and to identify cancer subtypes. Further, we propose that the device can be used for monitoring of cancer patients during and after treatment. The chemical nature of the cancer biomarkers will be identified through spectrometry techniques.The proposed approach would be used outside specialist settings and could considerably lessen the burden on the health budgets, both through the low cost of the proposed all-inclusive cancer test, and through earlier and, hence, more cost-effective cancer treatment.