Microarrays are a sensitive, specific, miniaturized devices that may be used to detect selected DNA sequences and proteins, or mutated genes associated with human diseases. Several methods have been developed to detect the binding of complementary molecules to microarrays by generating an optical signal. One of the most commonly used molecular labeling methods at present is fluorescence, but its application is expensive due to sophisticated equipment required to design the platform, hybridize it, and interpret the images derived from microarray-based studies. This is a drawback for its use in laboratories and clinical services. Another less expensive procedure having similar sensitivity and specificity is DNA and protein functional nanoparticles (FNP). Nanoparticles are sphere-like biocompatible materials made of inert silica, metal or crystals of a nanometer in size, which are generally coated with a thin gold layer. They may be used as hybridization probes in single nucleotide polymorphism (SNP) screening and to detect biological markers for cancer, infection, and cardiovascular diseases.