Search PubMedSearch

PubMed · 8573836

A nitric oxide sensor using reduction current.

Abstract

Nitric oxide (NO) has a wide range of biologic activity. Methods commonly used for the detection of biologically derived NO are indirect and measure only the amount of NO released during an interval of time. An electrochemical method available is capable of being direct and continuous but is subject to interference. The recent explosion of scientific research into NO activity requires better methods of NO detection. This article reports a new NO electrochemical sensing method and sensor design. The tip of the sensor is covered with a hydrophobic membrane and contains an internal electrolyte. Platinum is used for the working and counter electrodes and silver/silver bromide (Ag/AgBr) for the reference electrode. The components of the internal electrolyte are potassium bromide and sulfuric acid. The NO that diffuses to the working electrode is first oxidized to NO+; the NO+ is reduced to NO; and the reduction current is determined. An integrated pulsed amperometric method is used to achieve the redox of NO and the measurement and integration of the reduction current. The results show that the NO sensor is sensitive and has a rapid response and less interference.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

W Xu, S J Yao, S K Wolfson. A nitric oxide sensor using reduction current.. https://doi.org/10.1097/00002480-199507000-00042

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

From host response to genomic targets: electrochemical biosensing of tuberculosis biomarkers.

Tuberculosis (TB) remains one of the leading causes of death from a single infectious agent worldwide, with timely diagnosis continuing to be a major challenge, particularly in resource-limited settings. Conventional TB diagnostic methods are limited by low sensitivity, long turnaround times, and an inability to reliably differentiate latent from active disease. Biomarker-based diagnostic strategies have therefore gained increasing attention as they offer the potential to improve early detection, disease differentiation, and treatment monitoring. Herein, we examine electrochemical biosensing strategies for TB diagnostics using a biomarker-class-driven framework, covering host-response biomarkers (IFN-γ and TNF-α), pathogen-derived antigens (ESAT6, CFP10, CFP10-ESAT6, MPT64, Ag85, HspX and LpqH), cell-wall signatures and whole-cell markers (LAM and whole cell Mtb), and genomic markers (Mtb DNA and IS6110). Through structured comparison of recognition elements, biointerface designs, signal amplification strategies, electrochemical techniques, matrices, and validation levels, this review identifies the most promising technical approaches for different TB biomarker classes. It further highlights key translational bottlenecks, including limited clinical validation, buffer-based testing, complex multistep amplification, redox-probe dependence, matrix fouling, and insufficient evidence of manufacturability. This review therefore provides practical guidance for developing electrochemical TB biosensors that are analytically sensitive, clinically relevant, and suitable for decentralized diagnostic applications.

Biosensing Techniques

Metal-organic frameworks nanozyme-integrated portable microneedle patch for visual bacterial monitoring in meat.

Foodborne microbial contamination is a major global health concern, with conventional methods often being time-consuming and complex. Herein, we developed a novel portable biosensor by integrating microneedle patch technology and a metal-organic framework (Fe/Cu-NBDC MOF) nanozyme, enabling rapid, on-site, visual detection of bacteria in meat. The sensing system works by encapsulating aptamer-functionalized MOF nanozymes within a hydrogel patch, where their catalytic sites are initially blocked by the aptamer. In the presence of Staphylococcus aureus (S. aureus) as the target, the specific aptamer's binding to bacteria exposes numerous catalytic sites, further activating the chromogenic reaction of the tetramethylbenzidine‑hydrogen peroxide (TMB-H₂O₂) system, enabling visual detection of S. aureus. The biosensor demonstrates a detection limit of 82 CFU/mL with excellent specificity to successfully apply to commercial mutton. By integrating sampling, enrichment, and visual detection into a single compact device, this platform offers a practical, efficient solution for rapid on-site screening of foodborne pathogens.

Biosensing Techniques

A biotinylated conducting polypyrrole for the spatially controlled construction of an amperometric biosensor.

A new biotin derivative functionalized by an electropolymerizable pyrrole group has been synthesized. The electrooxidation of this biotin pyrrole has allowed the formation of biotinylated conducting polypyrrole films in organic electrolyte. Gravimetric measurements based on a quartz crystal microbalance, modified by the biotinylated polymer, revealed an avidin-biotin-specific binding at the interface of polymer-solution. The estimated mass increase corresponded to the anchoring of 1.5 avidin monolayers on the polypyrrole surface. In addition, the subsequent grafting of biotinylated glucose oxidase was corroborated by electrochemical permeation studies. Enzyme multilayers composed of glucose oxidase or polyphenol oxidase were elaborated on the electrode surface modified by the biotinylated polypyrrole film. The amperometric response of the resulting biosensors to glucose or catechol has been studied at +0.6 or -0.2 V vs SCE, respectively.

Biosensing Techniques