Optical microscopy technology has achieved great improvements in the 20th century. The detection limit has reached about twenty nanometers (with near-field optics, STED, PALM and STORM). But in the application areas such as life science, medical science, clinical treatment and especially in vivo dynamic measurement, mutual restrictions still exist between numeric aperture/magnification and working distance, fluorescent dependent, and between resolution and frame rate/field size, etc. This paper explores a hyperspectral scanning super-resolution label free molecules imaging method based on the white light interferometry. The vertical detection resolution was approximate to 1 nm which is the thickness of a single molecular layer and dynamic measuring range of thickness reaches to 10 μm. The spectrum-shifting algorithm is developed for robust restructure of images when the pixels are overlapped. Micro-biochip with protein binding and DNA amplification could be detected by using this spectral scanning super-resolution molecules imaging in label free. This method has several advantages as following: Firstly, the decoding and detecting steps are combined into one step. It makes tests faster and easier. Secondly, we used thickness-coded, minimized chips instead of a large microarray chip to carry the probes. This accelerates the interaction of the biomolecules. Thirdly, since only one kind of probes are attached to our thickness-coded, minimized chip, users can only pick out the probes they are interested in for a test without wasting unnecessary probes and chips.
This work presents a visualization method for the high-throughput monitoring of antibody-polypeptide binding by integrating a microarray chip with surface plasmon resonance imaging (SPRi). A prism-coupled SPRi system with smart images processing software and a 5×5 polypeptide microarray was developed. The modeling analysis was performed to optimize the system and the materials of prism and chip, looking for the optimal incident wavelength and angle of incidence for dynamic SPRi detection in solution. The system can dynamically monitor 25 tunnels of biomolecule interactions in solution without secondary tag reactants. In addition, this system can determine the specific profile of antibody-polypeptide binding in each tunnel and yield a visual three-dimensional histogram of dynamic combinations in all microarray tunnels. Furthermore, the detection limit of the label-free antibody-polypeptide binding reached 1 pg/μL in a one-step binding test, and an ultrasensitive detection of 10 fg/μL was obtained using three-step cascade binding. Using the peptide microarray, the amount of sample and reagents used was reduced to 80 nL per tunnel, and 20×20 tunnels of biomolecule interactions could be analyzed in parallel in a 7 mm×7 mm microreaction cells. This device and method offer a potential platform for high-throughput and label-free dynamic monitoring multiple biomolecule interactions for drug discovery and basic biomedical research.