A novel dual-mode aptasensor based on a multiple amplification system for ultrasensitive detection of lead ions using fluorescence and surface-enhanced Raman spectroscopy.

In this work, we develop a dual recycling amplification aptasensor for sensitive and rapid detection of lead ions (Pb2+) using fluorescence and surface-enhanced Raman scattering (FL-SERS). The aptasensor allows targeted cleavage of substrates through specifically binding with the Pb2+-dependent aptamer (M-PS2.M). Ultrasensitive detection of trace Pb2+ has been achieved using an enzyme-free nonlinear hybridization chain reaction (HCR) and the FL-SERS technique. The lower limit of detection (LOD = 3σ/k) is 0.115 pM in FL mode and 1.261 fM in SERS mode. The aptasensor is characterized by high reliability and specificity, among other things, to distinguish Pb2+ from other metal ions. In addition, the aptasensor can detect Pb2+ in actual water with good recovery. Compared with the single-mode aptasensor, the dual-mode aptasensor is characterized by high reliability, an extensive detection range, and high specificity.

CD47-mediated DTIC-loaded chitosan oligosaccharide-grafted nGO for synergistic chemo-photothermal therapy against malignant melanoma.

Nano-graphene oxide (nGO), an effective drug nanocarrier, is used for simultaneous photothermal therapy (PTT) and near-infrared fluorescence imaging. Dacarbazine (DTIC) is used in the treatment of melanoma with limited clinical efficacy. PTT shows promise in the treatment of skin cancer. Herein, chitosan oligosaccharide (COS)-grafted nGO was further modified with CD47 antibody, and loaded DTIC was prepared using a versatile nanoplatform (nGO-COS-CD47/DTIC) for the treatment of melanoma as a synergistic targeted chemo-photothermal therapy. The in vitro results demonstrated that nGO-COS-CD47/DTIC nanocarriers have excellent biocompatibility, photothermal conversion efficiency, high targeting efficiency, fast drug release under NIR irradiation, and tumor cell killing efficiency. Notably, nGO-COS-CD47/DTIC plus NIR irradiation significantly promoted early cell apoptosis through the mitochondrial apoptosis pathway and exhibited a significant joint function of antitumor efficacy. The demonstrated nGO-COS-CD47/DTIC can provide a highly efficient malignant melanoma therapy using this multifunctional intelligent nanoplatform.

In-situ Formation of Amorphous Co-Al-P Layer on CoAl Layered Double Hydroxide Nanoarray as Neutral Electrocatalysts for Hydrogen Evolution Reaction.

Exploration of high-efficiency and inexpensive electrode catalysts is of vital importance for the hydrogen evolution reaction (HER). In this research, an amorphous Co-Al-P layer was constructed on the surface of CoAl layered double hydroxide (CoAl-LDH) via an in-situ wet phosphidation strategy. The core-shell CoAl-LDH@Co-Al-P on Ti mesh (CoAl-LDH@Co-Al-P/TM) as an active HER electrocatalyst demands an overpotential of 150 mV to achieve a current density of 10 mA cm-2 at neutral pH. Moreover, CoAl-LDH@Co-Al-P/TM also exhibits good electrochemical stability and a superior Faradic efficiency of nearly 100%.

FeCoNi Sulfides Derived From In situ Sulfurization of Precursor Oxides as Oxygen Evolution Reaction Catalyst.

It is highly promising to design and develop efficient and economical electrocatalysts for oxygen evolution reaction (OER) in alkaline solution. In this work, we prepare FeCoNi sulfide composites (including FeS, Co3S4, and Ni3S4) derived from in situ sulfurization of precursor oxides on carbon cloth (CC), which are used to become an OER catalyst. Such catalyst shows excellent OER performance, low overpotential, small Tafel slope, and high electrochemical stability, and it is a promising electrocatalyst for OER in alkaline media.

A Ni(OH)2-CoS2 hybrid nanowire array: a superior non-noble-metal catalyst toward the hydrogen evolution reaction in alkaline media.

The rising H2 economy urgently demands active, durable and cost-effective catalysts for the electrochemical hydrogen evolution reaction (HER). However, improving the HER performance of electrocatalysts in alkaline media is still challenging. Herein, we report the development of a nickel hydroxide-cobalt disulfide nanowire array on a carbon cloth (Ni(OH)2-CoS2/CC) as a hybrid catalyst to significantly enhance the HER activity in alkaline solutions. Benefitting from heterogeneous interfaces in this 3D hybrid electrocatalyst, Ni(OH)2-CoS2/CC shows superior HER activity with only 99 mV overpotential to drive a current density of 20 mA cm-2 in 1.0 M KOH, which is 100 mV less than that of CoS2/CC. Moreover, Ni(OH)2-CoS2/CC exhibits long-term electrochemical durability with the maintenance of its catalytic activity for 30 h. Density functional theory calculations are performed to gain further insight into the effect of Ni(OH)2-CoS2 interfaces, revealing that Ni(OH)2 plays a key role in water dissociation to hydrogen intermediates and CoS2 facilitates the adsorption of hydrogen intermediates and H2 generation. This work not only develops a promising electrocatalyst for the alkaline HER, but also paves a way to enhance the alkaline HER activity of CoS2via the interface engineering strategy.

Amorphous Nickel-Cobalt-Borate Nanosheet Arrays for Efficient and Durable Water Oxidation Electrocatalysis under Near-Neutral Conditions.

Electrolytic hydrogen generation needs earth-abundant oxygen evolution reaction electrocatalysts that perform efficiently at mild pH. Here, the development of amorphous nickel-cobalt-borate nanosheet arrays on macroporous nickel foam (NiCo-Bi/NF) as a 3D catalyst electrode for high-performance water oxidation in near-neutral media is reported. To drive a current density of 10 mA cm-2 , the resulting NiCo-Bi/NF demands an overpotential of only 430 mV in 0.1 m potassium borate (K-Bi, pH 9.2). Moreover, it also shows long-term electrochemical durability with maintenance of catalytic activity for 20 h, achieving a high turnover frequency of 0.21 s-1 at an overpotential of 550 mV.