''Electrochemical nano-sensors'' and Absorption voltammetry method surface nanomolecules (Stripping Adsorption Voltammetry)

Note: In the construction of electrochemical nano-biosensors, the minimum parts used in a biosensor are: layer recognition molecular and signal transducer that can transmit this signal to a device (device readout). Are connected.DNA is usually a good tool as a biosensor because the base-pairing reaction between complementary play sequences is both specific and stable. In this case, the single-stranded probe DNA is immobilized on the detection layer and then reacts with the probe on the surface by pairing the target DNA. The duplication and uniqueness of DNA structures determines their accumulation on the surface. It is on this surface that the target DNA is captured and a signal is generated. Therefore, immobilizing the nucleic acid of the probe while maintaining its initial adhesion strength is important for detecting target DNA. But how this diagnostic procedure is measured depends on the method of the transduction signal, which may be optical, mechanical, or electrochemical.Optical biosensors based on fluorescent light have features. These types of biosensors are sensitive to molecules per square centimeter. They are made up of rows that are که so that their detection limit is made up of almost thousands of probes. Because the tools in this field (fluorescence biosensor) are complex and expensive . Gene chips technology is more suitable for laboratory work. Gene chips are appropriate in cases where a lot of work needs to be done at the same time, such as profiling transcriptional examination or discovery of single nucleotide polymorphism, but clinical diagnoses usually require the collection of this large amount of data. What is important for molecular detection is capability Ensure recognition as well as generality regardless of the order of the game. Therefore, gene chips are not preferred for clinical diagnosis for reasons such as: they are expensive and the device is complex. Also, for other specific reasons, reading accuracy is reduced. Another method for measuring the signal optically is the Resonance Plamon Surface method. In this method, the refractive index of a thin metal film substrate is changed, which is due to the adsorption of analyte and is suitable for detecting the target in cases where the house is a groove groove. Because in this way we can achieve the target molecule where the detection limit, causing the signal to the hybridization signal strengthened. This can be done by increasing the amount of material that is on the surface of the film before or after attaching toIncreased target DNA. The resonant Plus surface method (SPR) is similar to the expensive and complex fluorescence method, which is why it is so expensive and complex that it is used more for research than for routine diagnostic work ; One method of measuring the signal by light, which is very clear, is the light reading method, in which single-stranded DNAs are labeled with gold nanoparticles, which easily change color due to hybridization in the order of the target game . Using silver staining, DNA analysis can be performed with this optical method on very small plates with high sensitivity . Although the use of gold nanoparticles may be expensive, but this method has the necessary sensitivity and simplicity for clinical diagnoses.