Role of Outer Surface Probes on Bullet-Shaped Asymmetric Solid-State Nanochannels for Lysozyme Protein Sensing.

Artificial solid-state nanochannels featuring precise partitions present a highly promising platform for biomarker detection. While the significance of probes on the outer surface (POS) has been relatively overlooked in the past, our research highlights their crucial role in biosensing. Furthermore, the contribution of POS on the bullet-shaped asymmetric nanochannels has not been extensively explored until now. Here, we fabricated a series of bullet-shaped nanochannels, each featuring a distinct asymmetric structure characterized by different tip- and base-pore diameters. These nanochannels were further modified with explicit distributions at the inner wall (PIW), the outer surface (POS), and their combination (POS + PIW) for lysozyme sensing. The impact of diameters, structural asymmetry, and surface charge density on the sensing efficacy of POS and PIW was thoroughly examined through experimental investigations and numerical simulations. POS demonstrates great individual sensing performance for lysozyme within a broad concentration range, spanning from 10 nM to 1 mM. Furthermore, it improves the sensitivity when combined with PIW, particularly within the nanochannels featuring the smaller base-pore diameter, resulting in a 2-fold increase in sensing performance for POS + PIW compared to PIW at a concentration of 10 nM. These findings are substantiated by numerical simulations that closely align with the experimental parameters. The contributions of POS are notably amplified in the presence of smaller base pores and a higher degree of asymmetry within the bullet-shaped nanochannels. These findings elucidate the mechanism underlying the role of POS within bullet-shaped asymmetric nanochannels and open up new avenues for manipulating and enhancing the sensing efficiency.

Construction of layered hierarchical CoMoO4 nanostructured arrays for supercapacitors with enhanced areal capacitance.

Layered hierarchical CoMoO4 nano-structured arrays grown on nickel foam were designed and synthesized by a two-step hydrothermal method following by annealing. With the increase in the nearly three times loading mass of active materials, the specific capacitance of the layered hierarchical CoMoO4 nano-structured arrays only shows a slight loss compared with the single-layer CoMoO4 nano-structured arrays, which dramatically improved the areal capacitance from 2.47 to 6.79 F cm-2. Also, the layered hierarchical CoMoO4 nano-structured arrays showed 94.8% capacitance retention after 2500 cycles, which is mainly due to the well-designed layered hierarchical structure and good conductivity.