www.angewandte.org gami, [6] and other types of unconventional nucleic acids (Figure 1), [3c, 7] that can replace traditional proteases and antibodies, possess independent structural functions, and perform specific biological non-genetic functions. [3a-c, 4a,b, 8] The concept of FNA was also used to generalize the nongenetic functions of nucleic acids (Figure 1). [9] Meanwhile, research on the combination and functions of FNAs, such as DNAzymes, aptazymes, and aptamers, and nanomaterials, Wentao Xu studied at China Agricultural University (BS 2001, PhD 2006) and conducted postdoctoral research there before joining the faculty. He is currently an associate professor in the College of Food Science and Nutritional Engineering at China Agricultural University. His research interest is functional nucleic acid biosensors and nanomaterials. Wanchong He obtained his BS degree from Huazhong Agricultural University in 2017. He is now a PhD candidate in the College of Food Science and Nutritional Engineering at China Agricultural University. His research interest is functional nucleic acid biosensors.

Solid-state nanochannels demonstrating excellent mechanical properties and chemical stability combined with programmable DNA provide an opportunity to control on-demand ion transport. However, poor functionalization of the nanochannels limits the types of detected targets, as well as its universality in the sensing field. To solve these issues, a universal nanochannel sensing platform was developed by employing a nick hybridization chain reaction (nHCR) nanostructure as a molecular gate, which could generally respond to the universal sequence Y. Metal ion-dependent DNAzyme cleavage was used to transfer the chromium(III) (Cr 3+ ) ions into nucleic acid X, which was further amplified and converted into universal sequence Y. Upon adding sequence Y into the nHCR nanostructure-functionalized nanochannel, the disassembly of the nHCR molecular gate turned on the ionic current signal inside the nanochannel. The ON−OFF ratio displayed a linear relationship with the Cr 3+ concentration in the range from 200 fM to 20 nM. In less than 66 min, the nanochannel-based biosensing platform successfully detected Cr 3+ ions as low as 200 fM. In addition, the detection of microRNA with a concentration as low as 1 pM was achieved by only regulating the sequence of template X′−Y′.

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Realizing high‐precise and adjustable regulation of engineering nanozyme is important in nanotechnology. Here, Ag@Pt nanozymes with excellent peroxidase‐like and antibacterial effects are designed and synthesized by nucleic acid and metal ions coordination‐driven one‐step rapid self‐assembly. The adjustable NA‐Ag@Pt nanozyme is synthesized within 4 min using single‐stranded nucleic acid as templates, and peroxidase‐like enhancing FNA‐Ag@Pt nanozyme is received by regulating functional nucleic acids (FNA) based on NA‐Ag@Pt nanozyme. Both Ag@Pt nanozymes that are developed not only has simple and general synthesis approaches, but also can produce artificial precise adjustment and possess dual‐functional. Moreover, when lead ion‐specific aptamers as FNA are introduced to NA‐Ag@Pt nanozyme, the Pb2+ aptasensor is successfully constructed by increasing electron conversion efficiency and improving the specificity of nanozyme. In addition, both nanozyme has good antibacterial properties, with ~100% and ~85% antibacterial efficiency against Escherichia coli and Staphylococcus aureus, respectively. This work provides a synthesis method of novelty dual‐functional Ag@Pt nanozymes and successful application in metal ions detection and antibacterial agents.

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