Development of logic gates and half adders for the concurrent detection of two DNA molecules

Abstract

In this study, Graphene oxide/gold nanoparticles composite membrane electrodes (GCE/GO/AuNPs) were fabricated using drop coating and electrodeposition techniques. By analyzing changes in the probe's surface configuration before and after binding with target DNA, the electrochemical signal varies, enabling the intelligent detection of E. coli and Salmonella DNA. Take the target as the input signal, and Σ|ΔI| and |ΔI_MB/ΔI_FC| constructs “and” and “XOR” DNA molecular logic gates for output, and proposes a new semi adder model that can be used for logic operations. Square wave voltammetry (SWV) was used to detect the current change value Σ|ΔI| of the two labeled probes, which was consistent with E. The logarithmic values of the concentrations of coli DNA and Sal DNA showed a good linear relationship in the range of 1.0 × 10⁻¹³ to 1.0 × 10⁻⁸ mol·L⁻¹, and the detection limits (S/N = 3) were respectively 3.2 × 10⁻¹⁴ mol·L^–1 and 1.7 × 10⁻¹⁴ mol·L⁻¹.