Copper ion concentration detection based on quantum weak measurement of circular dichroism

Abstract

In this paper, a high precision detection method of copper ion (Cu2+) concentration based on weak measurement is proposed. The ternary complex formed by Cu2+ with L-tryptophan and phenanthroline reagents has circular dichroism (CD) signal at 605 nm in visible light. The CD signal can be obtained using the intensity contrast as a pointer in the imaginary weak-value amplification scheme. The measured sensitivity and resolution are 0.3417 mradl/mg and 0.058 mg/l, respectively, which is improved by an order of magnitude compared to the traditional CD measurement method. It is also more accurate and less costly than commonly used Cu2+ detection methods. The Cu2+ concentration detection based on the weak measurement of CD signal detection proposed in this paper not only brings technological breakthroughs in the field of heavy metal ion detection, but also is of great significance in promoting the cross-development of chemistry, biomedicine, and life sciences.