A manganese(II) complex with a ligand containing an oxidizable quinol group serves as a turn-on sensor for H2O2. Upon oxidation, the relaxivity of the complex in buffered water increases by 0.8 mM(-1) s(-1), providing a signal that can be detected and quantified by magnetic resonance imaging. The complex also serves as a potent antioxidant, suggesting that this and related complexes have the potential to concurrently visualize and alleviate oxidative stress.

Electrochemical affinity biosensors that can operate in whole blood are a rarity because biofouling of electrode surfaces compromises the performance of the final device. The common anti-biofouling layers that can be applied to electrodes, poly­(ethylene glycol) (PEG) or oligo­(ethylene glycol) (OEG) layers, form a high impedance layer on the electrode, effectively passivating the electrode. In response to this issue, we have developed effective anti-biofouling chemistry, that employs short chain zwitterionic species, derived from aryl diazonium salts, that give low impedance layers compatible with amperometry. Herein, we demonstrate the application of this surface chemistry to mixed layers of phenyl phosphorylcholine (PPC) and phenyl butyric acid (PBA), to develop immunosensors that can be used in whole blood. The capability of these new modification layers is demonstrated with an immunosensor for detecting tumor necrosis factor α in whole blood. The immunosensor is shown to specifically and precisely detect TNF-α in whole blood samples with a minimum detection limit of 10 pg/mL with a wide linear range of 0.01 ng/mL to 500 ng/mL. The results are comparable with those from commercial ELISA kit, indicating the developed immunosensor has great potential for future clinic use.

Three-dimensional hierarchically porous carbon-CNT-graphene ternary all-carbon foams (3D-HPCFs) with 3D macro- and mesoporous structures, a high specific surface area (1286 m(2) g(-1)), large bimodal mesopores (5.1 and 2.7 nm), and excellent conductivity have been fabricated through multicomponent surface self-assembly of graphene oxide (GO)-dispersed pristine CNTs (GOCs) supported on a commercial sponge. The commercial sponge with a 3D interconnected macroporous framework not only is used as a support for GOCs and subsequently multicomponent self-assembly but also serves as a 3D scaffold to buffer electrolytes to reduce ion transport resistance and ion diffusion distance, while the GO acts as "surfactant" to directly disperse pristine CNTs, preserving the excellent electronic structure of pristine CNTs, and the CNTs also prevent the aggregation of graphene as well as improve the whole conductivity. Benefiting from the aforementioned characteristics, the 3D-HPCFs-based supercapacitors show outstanding specific capacitance, high rate capability, and excellent cycling stability, making them potentially promising for high-performance energy storage devices.

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Small molecules, such as ferrocenemethanol (FcMeOH) and O2, that are capable of quenching the Ru(bpy)3(2+) excited state via energy or electron transfer can be quantitatively detected in a bipolar electrochemical cell based on the attenuation of steady-state electrogenerated chemiluminescence (ECL). FcMeOH quenches ECL generated by the Ru(bpy)3(2+) oxalate coreactant system, exhibiting a linear dependence on [FcMeOH] with a Stern-Volmer slope of 921 M(-1), corresponding to a quenching rate constant of 2 × 10(9) M(-1) s(-1). We used the bipolar ECL quenching platform to measure dissolved O2 and validated the results using a standard Clark electrode. The detection limit for local [O2] measured using ECL quenching was found to be 300 ppb. This work opens up the possibility of utilizing ECL quenching at bipolar electrodes for a wide range of applications.

Alexa Fluor 647 is a widely used fluorescent probe for cell bioimaging and super‐resolution microscopy. Herein, the reversible fluorescence switching of Alexa Fluor 647 conjugated to bovine serum albumin (BSA) and adsorbed onto indium tin oxide (ITO) electrodes under electrochemical potential control at the level of single protein molecules is reported. The modulation of the fluorescence as a function of potential was observed using total internal reflectance fluorescence (TIRF) microscopy. The fluorescence intensity of the Alexa Fluor 647 decreased, or reached background levels, at reducing potentials but returned to normal levels at oxidizing potentials. These electrochemically induced changes in fluorescence were sensitive to pH despite that BSA‐Alexa Fluor 647 fluorescence without applied potential is insensitive to pH between values of 4–10. The observed pH dependence indicated the involvement of electron and proton transfer in the fluorescence switching mechanism.

Alexa Fluor 647 is aw idely used fluorescent probe for cell bioimaging and super-resolution microscopy. Herein, the reversible fluorescence switching of Alexa Fluor 647 conjugated to bovine serum albumin (BSA) and adsorbed onto indium tin oxide (ITO) electrodes under electrochemical potential control at the level of single protein molecules is reported. The modulation of the fluorescence as af unction of potential was observed using total internal reflectance fluorescence (TIRF) microscopy. The fluorescence intensity of the Alexa Fluor 647 decreased, or reached background levels,a t reducing potentials but returned to normal levels at oxidizing potentials.T hese electrochemically induced changes in fluorescence were sensitive to pH despite that BSA-Alexa Fluor 647 fluorescence without applied potential is insensitive to pH between values of 4-10. The observed pH dependence indicated the involvement of electron and proton transfer in the fluorescence switching mechanism.