Zinc (Zn) is an excellent material for use as an anode for rechargeable batteries in water-based electrolytes. Nevertheless, the high activity of water leads to Zn corrosion and hydrogen evolution, along with the formation of dendrites on the Zn surface during repeated charge–discharge (CD) cycles. To protect the Zn anode and limit parasitic side reactions, an artificial solid electrolyte interphase (ASEI) protective layer is an effective strategy. Herein, an ASEI made of a covalent organic framework (COFs: HqTp and BpTp) was fabricated on the surface of a Zn anode via Schiff base reactions of aldehyde and amine linkers. It is seen that COFs can regulate the Zn-ion flux, resulting in dendritic-free Zn. COFs can also mitigate the formation of an irreversible passive layer and the hydrogen evolution reaction (HER). Zn plating/stripping tests using a symmetrical cell suggest that HqTpCOF@Zn shows superior stability and greater coulombic efficiency (CE) compared to bare Zn. The full cell having COFs@Zn also displays much improved cyclability. As a result, the COF proves to be a promising ASEI material to enhance the stability of the Zn anode in aqueous media.

Sulfur composites consisting of electrochemical reactive catalysts/conductive materials are investigated for use in lithium–sulfur (Li–S) batteries (LSBs). In this paper, we report the synthesis, physicochemical and electrochemical properties of CuZnS quantum dots (CZSQDs) decorated with nickel–cobalt–sulfide ((NiCo)–S)) mixed with reduced graphene oxide (rGO)/oxidized carbon nanotube (oxdCNT) (rGO/oxdCNT) ((NiCo)–S@rGO/oxdCNT) composites. These composites are for the purpose of being the sulfur host cathode in Li–S batteries. The as-prepared composites showed a porous structure with the CZSQDs being uniformly found on the surface of the rGO/oxdCNT, which had a specific surface area of 26.54 m²/g. Electrochemical studies indicated that the (NiCo)–S@rGO/oxdCNT cells forming the cathode exhibited a maximum capacity of 1154.96 mAhg⁻¹ with the initial discharge at 0.1 C. The smaller size of the CZSQDs (~10 nm) had a positive effect on the CZSQDs@(NiCo)–S@rGO/oxdCNT composites in that they had a higher initial discharge capacity of 1344.18 mAhg⁻¹ at 0.1 C with the Coulombic efficiency being maintained at almost 97.62% during cycling. This latter property is approximately 1.16 times more compared to the absence of the Cu–Zn–S QD loading. This study shows that the CuZnS quantum dots decorated with a (NiCo)–S@rGO/oxdCNT supporting matrix-based sulfur cathode have the potential to improve the performance of future lithium–sulfur batteries.

Electrowetting-on-dielectric (EWOD) is a microfluidic technology used for manipulating liquid droplets at microliter to nanoliter scale. EWOD has the ability to facilitate the accurate manipulation of liquid droplets, i.e., transporting, dispensing, splitting, and mixing. In this work, EWOD fabrication with suitable and affordable materials is proposed for creating EWOD lab-on-a-chip platforms. The EWOD platforms are applied for the diagnosis of early mortality syndrome (EMS) in shrimp by utilizing the colorimetric loop-mediated isothermal amplification method with pH-sensitive xylenol orange (LAMP–XO) diagnosis technique. The qualitative sensitivity is observed by comparing the limit of detection (LOD) while performing the LAMP–XO diagnosis test on the proposed lab-on-a-chip EWOD platform, alongside standard LAMP laboratory tests. The comparison results confirm the reliability of EMS diagnosis on the EWOD platform with qualitative sensitivity for detecting the EMS DNA plasmid concentration at 10² copies in a similar manner to the common LAMP diagnosis tests.

In this research, screen-printed graphene-carbon paste electrochemical electrodes (SPGEs) were fabricated on a single-plate electrowetting-on-dielectric (EWOD) digital microfluidic chip. The chip contained T-junction EWOD structures for merging buffer reagent and analyzed droplets and the electrochemical sensor based on SPGEs at the end of T-junction. The EWOD structures consisted of silver EWOD electrodes, a polydimethylsiloxane dielectric layer and Teflon®AF hydrophobic layers. The electrochemical sensor comprised a working SPGE, a counter SPGE, and a screen-printed silver/silver chloride reference electrode. Both EWOD and electrochemical electrodes were fabricated by a screen-printing technique. The digital microfluidic chip with the SPGE sensor was applied to mix and analyze three biochemical reagents including potassium hexacyanoferrate (K ₄ Fe(CN) ₆ ), nicotinamide adenine dinucleotide (NADH), and hydrogen peroxide (H ₂ O ₂ ). The electrochemical measurements were conducted using cyclic voltammetry over the concentration ranges of 10-500 μM, 10-500 μM, and 1000-7500 μM for K ₄ Fe(CN) ₆ , NADH,and H ₂ O ₂ , respectively. The results showed that the detection performances including sensitivity and detection limit of SPGE sensor on the EWOD chip were considerably better than those of screen-printed carbon paste electrodes.