Labelled and unlabelled probes for pathogen detection with molecular biology methods and biosensors

DNA probes are important tools in diagnostics to ensure high specificity and sensitivity. They are used in molecular biology methods like PCR, qPCR and hybridization techniques for an accurate detection of pathogens. The need for simple, easy to use, and rapid technologies has led to a great interest in the utilization of biosensors for diagnostic purposes. DNA probes can be utilized for the development of these new devices as they can be easily modified according to needs. Oligonucleotides can be labelled with different kind of molecules to produce detectable signals used for qualitative and quantitative assays. In this review a description of the probe design, in silico tests, and methods for immobilization are reported. Examples of applications of labelled and unlabelled probes in molecular biology methods (PCR, qPCR, hybridization techniques) and optical, electrochemical and quartz crystal microbalance biosensors are reported with examples of antigen-antibodies utilization. Aptamers are oligonucleotides with the same advantages of oligonucleotides probes, but they are able to attach to the surface of a whole cell. Thus, they are used for the construction of aptasensors, biosensors which utilize aptamers as bioreceptors