The Diamond Nanoscience group is based in the Department of Physics and Astronomy of Macquarie University, close to Sydney. We are part of the Centre of Excellence for Engineered Quantum Systems. The group involves cross-disciplinary research activity including the growth and the post-processing of nanodiamonds for their application in emerging fields of single particle probing, of magnetic nanosensors and microscopy. The studies undertaken include the use of fundamental quantum optics experiments, material science experiments and a combination of chemical physics approaches. The main area of application resides in nanotechnology, quantum nano-photonics and nanosensors, with the aim of implementing quantum technologies to enhance measurement capabilities not presently possible and to spur novel nanoscopy methods in life science. Presently our investigations, for application in life science, are focussed on sensing the magnetic field produced by spins in complex biological molecules. Other applications in physics can also benefit from our research, such as detection of magnetic resonance signals from individual electrons or nuclei, and the readout of classical or quantum bits of information encoded in an electron or nuclear spin memory.