The methods, apparatus and compositions disclosed herein concern the
detection, identification and/or sequencing of biomolecules, such as
nucleic acids or proteins. In certain embodiments of the invention, coded
probes comprising a probe molecule attached to one or more nanobarcodes
may be allowed to bind to one or more target molecules. After binding and
separation from unbound coded probes, the bound coded probes may be
aligned on a surface and analyzed by scanning probe microscopy. The
nanobarcodes may be any molecule or complex that is distinguishable by
SPM, such as carbon nanotubes, fullerenes, submicrometer metallic
barcodes, nanoparticles or quantum dots. Where the probes are
oligonucleotides, adjacent coded probes hybridized to a target nucleic
acid may be ligated together before alignment and scanning probe
microscopy (SPM) analysis. Compositions comprising coded probes are also
disclosed herein. Systems for biomolecule analysis may comprise an SPM
instrument and at least one coded probe attached to a surface.