Iranian researchers from Yazd University produced a biosensor that is able to determine fetus sex in a short period of time.
The sensor has high selectivity and sensitivity and can be produced at a low cost. Efforts were made in the designing of the sensor to use high performance nanoparticle and preferably an appropriate production method.
Common old methods for sex determination such as anatomic methods require high-tech devices, and errors are sometimes observed in the results. PCR molecular determination methods do not have appropriate sensitivity, and moreover, these methods are very time consuming and expensive. The researchers have presented a method in this research, which can determine the fetus sex at early stages of the fetus formation at very low concentrations of DNA (even at picomolar scale).
The electrochemical method was used in this research to produce gold nanoparticle. The reason for this choice can be explained by the advantages of this method such as the simplicity of the method in comparison with chemical method, high rate in the production of nanoparticle, the lack of contamination of the nanoparticle with chemicals, and the ability to control the size of nanoparticle only by controlling the current and potential.
Carbon paste electrode was firstly produced for the production of the sensor. The surface of the electrode was next coated with gold nanoparticles through cyclic voltammetry method. Then, DNA chain was connected to the nanoparticles. To this end, a solution of thiolated DNA was prepared with optimum concentration, and the electrodes were put in the solution for a determined period of time. The production of DNA chain in the solution was carried out by using specific enzyme in order not to use the time-consuming PCR method.
Results of the research have been published in Analytical Biochemistry, vol. 443, issue 2, December 2013, pp. 132-138.