We have developed an Atomic Force / Photon Scanning Tunneling Microscope (AF/PSTM) to eliminate the optical false image caused by topography of sample in PSTM. The key element of this system is bi-functional bent optical fiber probe, which can both be an optical cantilever and a device to collect the evanescent wave in near field of samples. In this paper, we derived a method to fabricate the bi-functional bent optical probes of AF/PSTM using communication optical fibers. The heated pulling combined with chemical etching method is proposed and developed. Fiber probes with an apex having a diameter smaller than 100nm could be produced with a controlled cone angles vary from 40 to 90 degrees. The back of the probe is finally coated with aluminum to enhance the reflection and with SiO<sub>2</sub> to prevent Al film from oxidating in the atmosphere. This method is straightforward and fast. Using probes made with this method, the images of biology samples are obtained and the image separation is realized.
Proc. SPIE. 5630, Optics in Health Care and Biomedical Optics: Diagnostics and Treatment II
KEYWORDS: Nanostructures, Refractive index, Biomedical optics, Statistical analysis, Atomic force microscopy, Biology, Near field scanning optical microscopy, Biological research, Scanning probe microscopy, Near field optics
As an analysis tool, SPM has been broadly used in biomedicine in recent years, such as AFM and SNOM; they are effective instruments in detecting life nanostructures at atomic level. Atomic force and photon scanning tunneling microscope (AF/PSTM) is one of member of SPM, it can be used to obtain sample’ optical and atomic fore images at once scanning, these images include the transmissivity image, reflection index image and topography image. This report mainly introduces the application of AF/PSTM in red blood membrane and the effect of different sample dealt with processes on the experiment result. The materials for preparing red cells membrane samples are anticoagulant blood, isotonic phosphatic buffer solution (PBS) and new two times distilled water. The images of AF/PSTM give real expression to the biology samples’ fact despite of different sample dealt with processes, which prove that AF/PSTM suits to biology sample imaging. At the same time, the optical images and the topography image of AF/PSTM of the same sample are complementary with each other; this will make AF/PSTM a facile tool to analysis biologic samples’ nanostructure. As another sample, this paper gives the application of AF/PSTM in immunoassay, the result shows that AF/PSTM is suit to analysis biologic sample, and it will become a new tool for biomedicine test.