AlGaN/GaN based heterostructures have attracted significant research interests in recent years for sensing very small scale displacement utlizing their unique piezoelectric properties. AlGaN/GaN heterojunction based Field Effect Transisitors (HFETs), when embedded at the base of a GaN cantilever, can be utilized to transduce a very small displacement with much higher Gauge Factor (GF) than their Si counterparts, by using the piezoelectric polarization induced change in two dimensional electron gas density at the heterojunction interface 12. Specifically, detection of femtometer level of photoacoustic signal was demonstrated using these ultra-sensitive piezotransistive microcantilevers 3. In this work, we have investigated the plasmonic effects of Au nanoparticles to dramatically enhance the magnitude of photoacoustic waves generated, which can have very significant impact on chemical and bio-analyte detection.