HIGH RESOLUTION FLUORESCENCE IMAGING WITH CANTILEVERED NEAR-FIELD FIBER OPTIC PROBES

High resolution near‐field fluorescence and topology images of intact neurons are reported using a cantilevered near‐field fiber optic probe. A bend is introduced into a normal geometry near‐field tip, allowing the probe to be used in a tapping‐mode arrangement, similar to tapping‐mode atomic force microscopy. Features with a full width at half‐maximum of 140 nm are observed in the near‐field fluorescence image, demonstrating the subdiffraction limit spatial resolution possible with the cantilevered near‐field probe design. Characteristics of the cantilevered tips include resonances between 30 and 60 kHz, Q factors greater than 100, and measured spring constants of 300 to 400 N/m.