Abstract
Nanomaterials have unique optical, electronic, or magnetic properties, thus explaining their potential applications in complex biosystems when coupled with biomolecules, such as DNA, peptides, proteins, or carbohydrates. With a large surface-to-volume ratio and homogeneity in aqueous solutions, various biomolecule-conjugated nanomaterials are exploited for elucidating biological interactions. During the past decade, biomolecule-conjugated nanoparticles (NPs) have been prepared and used in diagnostics [1], creative therapeutics [2], biomolecular interactions [3], and in vivo cell imaging [4, 5]. For example, Mirkin et al. developed an ultrasensitive bio-barcode detection method based on oligonucleotide-conjugated gold NP (AuNP) for biomarkers in small amounts in complex biofluids [6]. Weissleder et al. fabricated antibody-conjugated iron oxide NPs and used them to enhance T2 signals in magnetic resonance imaging [7]. Since they have unique magnetic properties, diverse functionalized magnetic nanoparticles (MNPs) have been designed and prepared to purify target proteins from crude cell lysate by simple magnetic separation. Recently, the authors combined antibody-conjugated MNP with matrix-assisted laser desorption/ ionization-time of flight (MALDI-TOF) mass spectrometry (MS) as a rapid and cost-effective detection method for diagnosing disease markers in human sera [8-11]. Biomolecule-modified quantum dots (QDs) have also been demonstrated as having promising applications in in vivo imaging, including cell trafficking and targeting. Besides metallic NPs, carbon nanotubes (CNTs) have also been demonstrated to be powerful carriers and to be useful in biological systems because of their high surface utilization efficiency and good size uniformity. © 2011 Springer Science+Business Media, LLC.