Transdermal delivery of nanocarriers provides an alternative pathway to transporttherapeutic agents, alleviating pain, improving compliance of patients, and increasing overall effectiveness of delivery. In this work, enhancement of transdermal delivery of fluorescent nanoparticles and sulforhodamine B with assistance of oleic acid was visualized utilizing multiphoton microscopy (MPM) and analyzed quantitatively using multi-photon excitation-induced fluorescent signals. Results of MPM imaging and MPM intensity-based spatial depth-dependent analysis showed that oleic acid is effective in facilitating transdermal delivery of nanoparticles. ; http://scitation.aip.org/docserver/fulltext/aip/journal/apl/100/21/1.3701135.pdf?expires=1395627867&id=id&accname=424340&checksum=B3EDD26AB8DEBAA4EC42422C6BD174CD