SPM derives images from three dimensions, and also needs no sample preparation, sample transparency or vacuum system to operate. Images with magnifications ranging from hundreds of micrometres down to the atomic level could not previously be made with a single instrument, but SPM makes this possible. Researchers at CSIA have developed an ultrasensitive immunoassay technique that uses AFM-based detection of binding events that occur on supersmooth antibody surfaces. McDonnell and his colleagues are also investigating the use of AFM in clinical diagnosis. This work includes measuring the shape and size of immobilised red blood cells.
Current methods can give ambiguous results, making diagnosis of some conditions difficult.
Scanning probe techniques have added to the chemist's armoury for investigating the atomic-scale world. As new variations on the scanning- probe theme become available and some of the stranger artefacts of the instrument are understood, the technique is becoming applicable in more and more areas of study. It would appear that, thanks to SPM, entities like atoms and processes like catalysis have lost their mystique for good.