The present invention provides for a practical method of grafting oligo- and/or poly(ethyleneglycol) (OEG and/or PEG) derivatives onto hydrogen-terminated silicon surfaces, including the surfaces of silicon scanning probe microscopy (SPM) tips, by hydrosilylation of OEG and/or PEG-terminated alkenes. This invention is related to the development of silicon-based bio-devices, including biochips, biosensors such as SPM probes, microarrays, micro-fluidic systems, and implantable microdevices. This invention is also a practical method to modify (many) SPM probe tips with OEG/PEG derivatives and to subsequently modify the tip apex with functional single molecules to improve the specificity and resolution of AFM imaging and measurements. The functional molecules include the dendritic adsorbates with a functional group at their focal point and with or without a tripod-shaped framework.