In a recently published paper, we present an ultra-sensitive photoinduced enhanced Raman spectroscopy (PIERS) method to detect analytes at extremely low concentrations (one to three orders of magnitude lower than that of surface-enhanced Raman spectroscopy, SERS) by using a novel substrate named as 4N-in-1. 4N-in-1 substrate can be re-used for diagnostic and forensic applications at least 20 times by simple photocatalytic degradation. More detail can be found in the  article link.