DNA-programming multicolor silver nanoclusters for sensitively simultaneous detection of two HIV DNAs

Single silver nanoclusters (AgNCs) had weaker fluorescence intensity. The green-emitting AgNCs (λ ex 500 nm / λ em 565 nm) for HIV-1 detection produced strong fluorescence based on the enhanced effect of the G-rich sequence, while the orange-emitting AgNCs (λ ex 580 nm/λ em 630 nm) for HIV-2 detection generated bright fluorescent signals only in the nanoclusters dimer. In the presence of HIV-1 and HIV-2, the structure of the high fluorescence effect is opened and the fluorescence intensity of both color AgNCs is lowered. • A DNA-stabilized silver nanoclusters (AgNCs)-based probe for simultaneous detection of two HIV DNAs. • The designed probe is label-free, low-cost, facile synthesis and simple probe-preparation. • The strategy obtained a lower detection line of 11 pM and a wide detection range. A novel DNA-stabilized silver nanoclusters (AgNCs)-based label-free fluorescent platform for simultaneously detecting two human immunodeficiency virus oligonucleotides (HIV DNAs) was developed. The sensing platform was established based on fluorescence enhancement of guanine (G)-rich and the phenomenon in the process of two silver nanoclusters (AgNCs) forming a nanoclusters dimer. The probe (AgNCs/G) utilized for HIV-1 detection adopted an effective conformation based on enhancement effect of G-rich sequence (at 500 nm ex / 565 nm em) while the probe (AgNCs/AgNCs) for HIV-2 generated fluorescence signals (at 580 nm ex / 630 nm em) with bright fluorescence only in nanoclusters dimer. The nanoprobe shows high selectivity for multiplexed analysis of target DNA with a detection limit of 11 pM, respectively. Moreover, this is the first time to use the affectivity of fluorescent AgNCs and two HIV DNAs simultaneous detection integrated into a novel method, which shows a great promise in biomedical research and early clinical diagnosis.