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A novel three-dimensional (3D) electrochemical sensor was developed for highly sensitive detection of hydrogen peroxide (H2O2). Monolithic and macroporous graphene foam grown by chemical vapor deposition (CVD) served as the electrode scaffold. Using in-situ polymerized polydopamine as the linker, the 3D electrode was functionalized with thionine molecules which can efficiently mediate the reduction of H2O2 at close proximity to the electrode surface. Such stable non-enzymatic sensor is able to detect H2O2 with a wide linear range (0.4 to 660 μM), high sensitivity (169.7 μA mM−1), low detection limit (80 nM), and fast response (reaching 95% of the steady current within 3 s). Furthermore, this sensor was used for real-time detection of dynamic release of H2O2 from live cancer cells in response to a pro-inflammatory stimulant. Keywords: 3D graphene, Electrochemical sensing, Hydrogen peroxide, Thionine, Polydopamine

Owing to their extraordinary physicochemical, electrical, and mechanical properties, carbon nanotubes (CNTs) and graphene materials have been widely used to improve energy storage and conversion. In this article, we briefly review the latest development on fabrication of 3D porous structures of CNTs or graphene sheets or their hybrids, and their applications in various energy devices including supercapacitors, (bio-) fuel cells, and lithium ion batteries.

Owing to their small size, biocompatibility, unique and tunable photoluminescence, and physicochemical properties, graphene quantum dots (GQDs) are an emerging class of zero-dimensional materials promising a wide spectrum of novel applications in bio-imaging, optical, and electrochemical sensors, energy devices, and so forth. Their widespread use, however, is largely limited by the current lack of high yield synthesis methods of high-quality GQDs. In this contribution, a facile method to electrochemically exfoliate GQDs from three-dimensional graphene grown by chemical vapor deposition (CVD) is reported. Furthermore, the use of such GQDs for sensitive and specific detection of ferric ions is demonstrated.

Microfiber devices are able to extend the micro/nano functionalities of materials or devices to macroscopic scale with excellent flexibility and weavability, promising a variety of unique applications and, sometimes, also improved performance as compared with bulk counterparts. The fiber electrodes in these devices are often made of carbon materials (e.g., carbon nanotubes and graphene) because of their exceptional electrical, mechanical, and structural properties. Covering the latest developments and aiming to stimulate more exciting applications, we comprehensively review the preparation and applications of carbon-microfiber devices on energy conversion and storage, electronics, sensors and actuators. ASTAR (Agency for Sci., Tech. and Research, S’pore) Published version

Heteroatom doping can endow graphene with various new or improved electromagnetic, physicochemical, optical, and structural properties. This greatly extends the arsenal of graphene materials and their potential for a spectrum of applications. Considering the latest developments, we comprehensively and critically discuss the syntheses, properties and emerging applications of the growing family of heteroatom-doped graphene materials. The advantages, disadvantages, and preferential doping features of current synthesis approaches are compared, aiming to provide clues for developing new and controllable synthetic routes. We emphasize the distinct properties resulting from various dopants, different doping levels and configurations, and synergistic effects from co-dopants, hoping to assist a better understanding of doped graphene materials. The mechanisms underlying their advantageous uses for energy storage, energy conversion, sensing, and gas storage are highlighted, aiming to stimulate more competent applications. ASTAR (Agency for Sci., Tech. and Research, S’pore) Published version

In this work, a nanoporous thin film consisting of sieve-like tin oxide (SnO2) sheets was prepared by anodization of tin foil in aqueous ammonia and applied as a photoelectrode for dye-sensitized solar cell (DSSC). Compared to the conventional SnO2 nanoparticle-based photoelectrode, the anodized nanoporous SnO2 electrode offers higher short circuit current (6.85 vs. 3.64 mA/cm2) and open circuit voltage (0.56 vs. 0.51 V) due to better charge transportation and better suppression of charge recombination. Consequently, the power conversion efficiency of the DSSC equipped with the anodized SnO2 electrode is enhanced by 63%. Published version

Bovine colostrum is the milk secreted by cows during the first few days after parturition. It contains many essential nutrients and bioactive components, including growth factors, immunoglobulins (Igs), lactoperoxidase (Lp), lysozyme (Lys), lactoferrin (Lf), cytokines, nucleosides, vitamins, peptides and oligosaccharides, which are of increasing relevance to human health. Much research work has been done on the structure and function of bovine colostrum proteins. IgG was widely utilised in the immunological supplementation of foods, specifically in infant formulate, and yielded sales of approximately US$100 million in 2007 (Gapper, et al., 2007). In the highly competitive and valuable international market for IgG-containing products, some of the products are usually priced based on IgG content. Another important protein from bovine colostrum is lactoferrin. Its diverse range of biological activities such as anti-infective activities toward a broad spectrum of species, antioxidant activities and promotion of iron transfer are expanding the demand in the market. It also exhibits the potential for chemoprevention of colon and other cancers as a natural gradient. Apart from the two kinds of bovine colostrum proteins, ┙-lactalbumin has been claimed as an important food additive in infant formula due to its high content in tryptophan and as a protective against ethanol and stress-induced gastric mucosal injury. ┚Lactoglobulin is commonly used to stabilize food emulsions for its surface-active properties. Bovine serum albumin (BSA) has gelation properties and it is of interest in a number of food and therapeutic applications (Almecija, et al., 2007). Therefore, fractionation for the recovery and isolation of these proteins has a great scientific and commercial interest. As a result of this growth in the commercial use of bovine colostrum proteins, there is great interest in establishing more efficient, robust and low cost processes to purify them. Although great deals of studies have been done for the separation and purification of colostrum proteins due to their wide application in food industry, medicine and as supplements, large scale production system for the downstream processing of recombinant antibodies still represents the major issue. Lu (Lu, et al., 2007) designed a two-step ultrafiltration process followed by a fast flow strong cation exchange chromatography to isolate LF from bovine colostrum in a production scale. A stepwise procedure for purification of the crude LF was conducted using a preparative-scale strong cation exchange