An optical probe includes an optical fiber with a first end and a second end, and an enhanced surface on a portion of the first end of the optical fiber. The enhanced surface includes a patterned base layer including multiple protruding nano-pyramids, an intermediate layer over the patterned base layer, and a graphene layer over the intermediate layer. Using a layer of graphene to cover the enhanced surface increases the sensitivity of a surface-enhanced Raman spectroscopy (SERS) process performed in conjunction with the enhanced surface, and further increases the chemical stability and bio-compatibility of the enhanced surface. Further, placing the enhanced surface at the end of the optical fiber provides a self-contained probe for use with a SERS process, thereby allowing for in-vivo characterization of a sample.