Highly-sensitive mercury ion sensor based on DNA modified micro-nano fiber

Deoxyribonucleic acid (DNA) was modified on the surface of a non-adiabatic micro-nano fiber by electrostatic adsorption to detect the concentration of Hg²⁺ in water. Since Hg²⁺ specifically binds to DNA, the structure of DNA changes, and then the refractive index of fiber surface changes. Micro-nano fiber, which is very sensitive to the change of refractive index of solution, can convert the change of refractive index into the significant shift of interference wavelength. Therefore, by monitoring the shift of the resonance wavelength, the concentration of Hg²⁺ can be obtained. Such a combination can fully increase the detection sensitivity, which is 0.767nM/lgM in the range of 10^-15-10^-8M of Hg²⁺ concentration.