Confined synthesis of g-CN modified porous carbons for efficient removal of Cd ions.

Carbon nitride (CN) nanosheets have excellent adsorption capacity, environmental friendliness, and high stability for heavy metal removal. However, its application in Cd-polluted soil is difficult as aggregation induces the specific surface area to substantially decrease. In this study, a series of CN nanosheet-modified porous carbons (CN/PC-X) were prepared by a simple one-step calcination of mixed aerogels with different mass ratios (X) of carboxymethyl cellulose (CMC) and melamine.

A sensitive ratiometric fluorescent sensor based on carbon dots and CdTe quantum dots for visual detection of biogenic amines in food samples.

A novel dual-emission ratiometric fluorescent sensor for biogenic amines (BAs) was prepared by simple mixing blue fluorescent carbon dots (CDs) and yellow fluorescent CdTe quantum dots (CdTe QDs). Based on different sensitive properties of pH, CdTe QDs and CDs were used as the response signal and internal reference signal, respectively. The developed ratiometric fluorescent sensor achieved quantitative analysis of eight kinds of BAs with rapid response (30 s) and low limits of detection (1.

Colorimetric and ratiometric fluorescent dual-mode sensitive detection of Hg based on UiO-66-NH@Au composite.

A colorimetric and ratiometric fluorescent dual-mode assay is constructed for sensitive and specific Hg sensing based on UiO-66-NH and Au composite (UiO-66-NH@Au). The addition of Hg stimulates the peroxidase-like activity of UiO-66-NH@Au by the formation of Au-Hg amalgam, promoting the oxidizing of chromogenic substrate OPD to DAP with the aid of HO, which lead to the change of colorimetric and fluorescent signals. The absorbance of the sensing system at 450 nm is linear positive correlation with Hg concentration of 30-1400 nM and the color of the solution under visible light shaded from light yellow to dark yellow.

Regenerable magnetic aminated lignin/FeO/La(OH) adsorbents for the effective removal of phosphate and glyphosate.

Phosphates and organophosphorus cause environmental pollution, and excessive phosphate leads to water eutrophication. Glyphosate, an organophosphorus herbicide, harms the environment and human health. In this study, regenerable magnetic AL/FeO/La(OH) adsorbents were developed by modifying FeO and La(OH) on aminated lignin (AL) for phosphate and glyphosate removal.

A simple and sensitive sensor for lactose based on cascade reactions in Au nanoclusters and enzymes co-encapsulated metal-organic frameworks.

In this work, one kind of zeolite imidazole frameworks containing bovine serum albumin stabilized Au nanoclusters (AuNCs), β-galactosidase (β-Gal) and glucose oxidase (GOx) (AuNCs/β-Gal/GOx@ZIF-8) were obtained to detect lactose. Compared with other fluorescent nano-materials, AuNCs show distinct advantages as a guest species in ZIF-8, specifically their extremely small size (<1 nm), simple synthesis, excellent biocompatibility and high stability. Furthermore, the bovine serum albumin on their surfaces can promote the formation of ZIF-8 coating; thus, AuNCs were co-encapsulated in ZIF-8 with the enzymes together.

Fluorometric determination of mercury(II) based on dual-emission metal-organic frameworks incorporating carbon dots and gold nanoclusters.

Carbon dots and gold nanoclusters co-encapsulated by zeolitic imidazolate framework-8 (CDs/AuNCs@ZIF-8) have been obtained at room temperature. The composite has been applied to the ratiometric fluorescence determination of mercury(II). The composite shows fluorescence emission maxima at 440 and 640 nm under 360 nm excitation, due to the CDs and AuNCs, respectively (associated quantum yields were 18% and 17%, respectively).

A simple aptamer-based fluorescent aflatoxin B1 sensor using humic acid as quencher.

This work described a fluorometric and aptamer-based assay for aflatoxin B1 (AFB1). Aptamer-modified carbon dots (DNA-CDs) were first synthesized as fluorescence probes, then reacted with humic acid (HAs) which acted as quencher of the blue fluorescence of the CDs. It was found that HAs can readily adsorb ssDNA aptamers due to the presence of a rich surface chemistry (quinoidal units, aromatic rings and sugar moieties).

An electrochemical immunosensor based on an etched zeolitic imidazolate framework for detection of avian leukosis virus subgroup J.

A novel sandwich-type electrochemical immunosensor for avian leukosis virus subgroup J (ALV-J) is described. The immunosensor was prepared by first modifying a glassy carbon electrode (GCE) with reduced graphene oxide that was functionalized with tannic acid and magnetite nanoparticles (rGO-TA-FeO). Primary antibodies (Ab) were then deposited on the modified GCE.

A novel pH-responsive electrochemiluminescence immunosensor for ALV-J detection based on hollow MnO encapsulating Ru(bpy)Cl.

A novel pH-responsive sandwich-type electrochemiluminescence immunosensor was successfully developed for the detection of avian leukosis virus subgroup J (ALV-J). The immunosensor consisted of graphene oxide functionalized with tannic acid (rGO-TA) and primary antibodies (Ab) as the main ALV-J sensing platform. For signal amplification, pH-responsive hollow MnO (hMnO) nanospheres encapsulating Ru(bpy)Cl and carrying secondary antibodies (Ab) were employed.

A sensitive fluorescent sensor for selective determination of dichlorvos based on the recovered fluorescence of carbon dots-Cu(II) system.

In this paper, a simple and sensitive fluorescent sensor for dichlorvos was first constructed based on carbon dots-Cu(II) system. These carbon dots were obtained by simple hydrothermal reaction of feather. The fluorescence of these carbon dots can be selectively quenched by Cu(2+) ion.

Innovative approach for the electrochemical detection of non-electroactive organophosphorus pesticides using oxime as electroactive probe.

An innovative approach for sensitive and simple electrochemical detection of non-electroactive organophosphorus pesticides (OPs) was described in this report. The novel strategy emphasized the fabrication of an oxime-based sensor via attaching pralidoxime (PAM) on graphene quantum dots (GQDs) modified glassy carbon electrode. The introduction of GQDs significantly increased the effective electrode area, and then enlarged the immobilization quantity of PAM.

A simple and sensitive fluorescent sensor for methyl parathion based on L-tyrosine methyl ester functionalized carbon dots.

In this paper, a simple and sensitive fluorescent sensor for methyl parathion is developed based on L-tyrosine methyl ester functionalized carbon dots (Tyr-CDs) and tyrosinase system. The carbon dots are obtained by simple hydrothermal reaction using citric acid as carbon resource and L-tyrosine methyl ester as modification reagent. The carbon dots are characterized by transmission electron microscope, high resolution transmission electron microscopy, X-ray diffraction spectrum, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy.

Electroenzymatic oxidation of bisphenol A (BPA) based on the hemoglobin (Hb) film in a membraneless electrochemical reactor.

This paper presents a novel electroenzymatic method for the treatment of bisphenol A (BPA) in a membraneless electrochemical reactor. The electrochemical reactor was arranged with a stainless steel and an enzymatic film as anode and cathode, respectively. The enzymatic film was formed by immobilizing hemoglobin (Hb) on carbon fiber.