2 research outputs found
Stainless Steel Electrode for Sensitive Luminol Electrochemiluminescent Detection of H<sub>2</sub>O<sub>2</sub>, Glucose, and Glucose Oxidase Activity
Electrogenerated
chemiluminescence (ECL) application of stainless
steel, a robust and cost-effective material, has been developed for
the first time. Type 304 stainless steel electrode shows appealing
ECL performance in the luminol–H<sub>2</sub>O<sub>2</sub> system.
It enables the detection of H<sub>2</sub>O<sub>2</sub> with a linear
range from 1 to 1000 nM and a limit of detection of 0.456 nM [signal-to-noise
ratio (S/N) = 3]. The ECL method based on type 304 stainless steel
electrode is more sensitive, more cost-effective, and much simpler
than other ECL methods reported before. Because the stainless steel
electrode has excellent performance for H<sub>2</sub>O<sub>2</sub> detection and H<sub>2</sub>O<sub>2</sub> participates in many important
enzymatic reactions, applications of stainless steel electrode-based
ECL for detection of enzyme activities and enzyme substrates were
further investigated by use of glucose oxidase (GODx) and glucose
as representative enzyme and substrate. The concentrations of glucose
and the activity of GODx were directly proportional to ECL intensities
over a range of 0.1–1000 μM and 0.001–0.7 units/mL
with limits of detection of 0.076 μM and 0.00087 unit/mL (S/N
= 3), respectively. This method was successfully used for determining
glucose in honey. Because of their remarkable performance and user-friendly
features, stainless steel electrodes hold great promise in various
electroanalytical applications, such as biosensing, disposable sensors,
and wearable sensors
Determination of Concentrated Hydrogen Peroxide Free from Oxygen Interference at Stainless Steel Electrode
H<sub>2</sub>O<sub>2</sub> is frequently used at high concentrations
in various applications. It is very challenging to detect high concentrations
of H<sub>2</sub>O<sub>2</sub> and to eliminate oxygen interference
for H<sub>2</sub>O<sub>2</sub> detection through electrochemical reduction.
In the present investigation, the electrochemistry of H<sub>2</sub>O<sub>2</sub> at stainless steel electrode has been carried out for
the first time. A cathodic peak for H<sub>2</sub>O<sub>2</sub> reduction
was observed at about −0.40 V, and no cathodic peak for dissolved
oxygen reduction was observed on type 304 stainless steel electrode.
Amperometric determination of H<sub>2</sub>O<sub>2</sub> on type 304
stainless steel electrode displayed a linear range from 0.05 up to
733 mM with a detection limit of 0.02 mM (S/N = 3) and a sensitivity
of 16.7 μA mM<sup>–1</sup> cm<sup>–2</sup>. The
type 304 stainless steel electrode not only shows much higher upper
limit than other reported electrodes for the detection of concentrated
H<sub>2</sub>O<sub>2</sub> but also is free from oxygen interference,
which is of great importance for practical applications. This method
could detect H<sub>2</sub>O<sub>2</sub> in wound wash and lake water
with excellent recoveries. Moreover, we successfully applied the stainless
steel electrode to determine glucose using glucose oxidase to catalyze
the oxidation of glucose to generate hydrogen peroxide. The linear
range for glucose is between 0.5 and 25 mM, which covers clinically
important blood glucose concentrations well