Electrochemical Diagnosis of Urinary Tract Infection Using Boron-Doped Diamond Electrodes.

Efficient detection of sodium nitrite in human urine could be used to diagnose urinary tract infections rapidly. Here, we demonstrate a fast and novel method for the selective detection of sodium nitrite in different human urine samples using electrolysis with a bare boron-doped diamond electrode. The measurement is performed without adding any other species, such as enzymes, and uses a simple electrochemical approach with an oxidation step followed by reduction.

Urine protein quantification in human urine on boron-doped diamond electrodes based on the electrochemical reaction of Coomassie brilliant blue.

Urinalysis is attracting interest in personal healthcare management as part of a general move to improve quality of life. Urine contains various metabolites and the protein level in urine is an indicator of kidney function. In this study, a novel electrochemical sensing system based on boron-doped diamond (BDD) electrodes was developed for the detection of protein concentrations in human urine.

A strategy for low-cost portable monitoring of plasma drug concentrations using a sustainable boron-doped-diamond chip.

On-site monitoring of plasma drug concentrations is required for effective therapies. Recently developed handy biosensors are not yet popular owing to insufficient evaluation of accuracy on clinical samples and the necessity of complicated costly fabrication processes. Here, we approached these bottlenecks via a strategy involving engineeringly unmodified boron-doped diamond (BDD), a sustainable electrochemical material.

Analysis of Pharmacokinetics in the Cochlea of the Inner Ear.

Hearing loss affects >5% of the global population and therefore, has a great social and clinical impact. Sensorineural hearing loss, which can be caused by different factors, such as acoustic trauma, aging, and administration of certain classes of drugs, stems primarily from a dysfunction of the cochlea in the inner ear. Few therapeutic strategies against sensorineural hearing loss are available.

Nanoscale Reactivity Mapping of a Single-Crystal Boron-Doped Diamond Particle.

Boron-doped diamond (BDD) is most often grown by chemical vapor deposition (CVD) in polycrystalline form, where the electrochemical response is averaged over the whole surface. Deconvoluting the impact of crystal orientation, surface termination, and boron-doped concentration on the electrochemical response is extremely challenging. To tackle this problem, we use CVD to grow isolated single-crystal microparticles of BDD with the crystal facets (100, square-shaped) and (111, triangle-shaped) exposed and combine with hopping mode scanning electrochemical cell microscopy (HM-SECCM) for electrochemical interrogation of the individual crystal faces (planar and nonplanar).

Real-Time Simultaneous Examination of Drug Kinetics at Two Separate Locations Using Boron-Doped Diamond Microelectrodes.

Methylcobalamin, which is used for the clinical treatment of patients with neuropathy, can have an impact on the sensorineural components associated with the cochlea, and it is possible that the auditory threshold in a certain population of patients with deafness may be recovered. Nonetheless, it remains uncertain whether the action site of methylcobalamin is localized inside or outside the cochlea and which cellular or tissue element is targeted by the drug. In the present work, we developed a method to realize real-time simultaneous examination of the drug kinetics in two separate locations using boron-doped diamond microelectrodes.

An electrochemical aptamer-based sensor prepared by utilizing the strong interaction between a DNA aptamer and diamond.

Stable and continuous biosensing of electroactive species in vivo has been achieved by using boron-doped diamond (BDD) electrodes owing to their outstanding electrochemical properties. However, the present problem in biosensing using BDD electrodes is how to specifically measure/detect the target molecules, including electrochemically inactive species. A possible solution is to fabricate an electrochemical aptamer-based (E-AB) sensor using a BDD electrode.

[Development of in vivo drug sensing system with needle-type diamond microelectrode].

Continuous and real-time measurement of local concentrations of systemically administered drugs in vivo must be crucial for pharmacological studies. Nevertheless, conventional methods require considerable samples quantity and have poor sampling rates. Additionally, they cannot determine how drug kinetics correlates with target function over time.

Fabrication of an all-diamond microelectrode using a chromium mask.

We have developed a new method for fabricating all-diamond microelectrodes. The process comprises three steps: masking the tip of an electrode by electroplating with chromium, depositing undoped diamond, which acts as an insulator on the sides of the electrode, and removing the chromium mask to expose the tip of the electrode. The active area of the electrode can be easily controlled in combination only with a conventional electroplating technique.

A microsensing system for the in vivo real-time detection of local drug kinetics.

Real-time recording of the kinetics of systemically administered drugs in in vivo microenvironments may accelerate the development of effective medical therapies. However, conventional methods require considerable analyte quantities, have low sampling rates and do not address how drug kinetics correlate with target function over time. Here, we describe the development and application of a drug-sensing system consisting of a glass microelectrode and a microsensor composed of boron-doped diamond with a tip of around 40 μm in diameter.

Phase 1 study of sulfasalazine and cisplatin for patients with CD44v-positive gastric cancer refractory to cisplatin (EPOC1407).

A previous dose-escalation study of sulfasalazine (SSZ), an inhibitor of cystine-glutamate exchange transporter xc (-), in the variant form of CD44 (CD44v)-positive cancer stem cells (CSCs) suggested that administration of SSZ induces the reduction of CD44v-positive cells and intracellular reduced glutathione (GSH) levels in patients with advanced gastric cancer (AGC). Here we report a study to evaluate SSZ in combination with cisplatin in patients with CD44v-expressing AGC refractory to cisplatin. SSZ was given by oral administration four times daily with 2 weeks on and 1 week off.

Continuous and selective measurement of oxytocin and vasopressin using boron-doped diamond electrodes.

The electrochemical detection of oxytocin using boron-doped diamond (BDD) electrodes was studied. Cyclic voltammetry of oxytocin in a phosphate buffer solution exhibits an oxidation peak at +0.7 V (vs.