Gunawan et al.
ALCHEMY Jurnal Penelitian Kimia.
Vol.
2025, 43-52
ALCHEMY Jurnal Penelitian Kimia Official Website: https://jurnal.
id/alchemy Cyclic Voltammetry Study of the Influence of Concentration of K3[Fe(CN).
and Glucose on Glassy Carbon Electrode1 Adella Fajaretta Gunawana,c.
Arie Hardianb, c.
Anceu Murniatib,c* Department of Chemistry.
Faculty of Sciences and Informatics.
Jenderal Achmad Yani University Jalan Terusan Jenderal Sudirman.
Cimahi Selatan.
Cimahi.
Jawa Barat 40513.
Indonesia Department of Master Chemistry.
Faculty of Sciences and Informatics.
Jenderal Achmad Yani University Jalan Terusan Jenderal Sudirman.
Cimahi Selatan.
Cimahi.
Jawa Barat 40513.
Indonesia Material and environmental development center of Jenderal Achmad Yani University Jalan Terusan Jenderal Sudirman.
Cimahi Selatan.
Cimahi.
Jawa Barat 40513.
Indonesia Corresponding author: anceu.
murniati@lecture.
DOI: 10.
20961/alchemy.
Received 4 June 2024.
Revised 17 October 2024.
Accepted 19 October 2024.
Published 28 March 2025 Keywords:
cyclic voltammetry.
glassy carbon scan rate.
ABSTRACT.
Biosensors are cost-effective, user-friendly devices with rapid response, sensitivity, selectivity, and stability.
This study investigated the impact of K3[Fe(CN).
concentration and glucose on glassy carbon electrode (GCE) performance.
The cyclic voltammetry method determined the effects of varying K3[Fe(CN).
and glucose concentrations on GCE.
GCE characterization utilized K 3[Fe(CN).
Ae 5 mM) in 0.
2 M KCl and achieved an optimum scan rate of 75 mV/s within -1.
5 to 1 V vs.
Ag/AgCl.
Reversible Fe2 /Fe3 redox occurred at 1mM .
pa/ipc= 0.
, with the highest reduction peak at Glucose tests .
mM to 5mM) in 0.
1 M NaOH exhibited an optimal scan rate of 200 mV/s within a potential range of -10 Ae 10 V at 1 mM .
pa/ipc= 1.
, with the highest oxidation peak at 5 mM.
GCE
effectively measured concentration effects, with ipa/ipc values close to 1, indicating reversible redox processes at low concentrations.
Higher concentrations yielded stronger peak currents due to increased electroactive species.
INTRODUCTION
A biosensor is a chemical sensing device that converts signals generated by biochemical reactions.
The advantages of biosensors include affordability, ease of use, speed in measurement, high sensitivity, selectivity, and high stability (Dorledo de Faria et al.
, 2.
The main components of biosensors are bioreceptors and transducers.
The bioreceptor is a biomolecule that specifically recognizes the target analyte, while the transducer converts the binding event into a measurable signal (Jaiswal and Tiwari, 2.
Electrochemical sensors in glucose biosensors show great potential because they have outstanding characteristics, including ease of use, simplicity, sensitivity, selectivity, and time-saving capabilities.
These sensors also play an important role in the redox process of atomic non-enzymatic sensors capable of direct surface detection (Zhang et al.
, 2.
The chemical processes in sugars involve oxidation, reduction, and glycosylation, which are essential for synthesizing sugar nucleotides and other organic compounds (Mikkola, 2.
Although non-enzymatic glucose sensors offer better long-term stability than enzymatic glucose biosensors, they have a lower level of selectivity due to challenges in the ability of electrocatalytic materials to catalyze glucose oxidation specifically (Hassan et al.
, 2.
Using non-enzymatic analysis methods overcomes the limitations of enzymatic methods, which require several conditions for the enzyme to function.
Fourth-generation non-enzymatic glucose biosensors can facilitate glucose oxidation without the need for enzymes by utilizing the electrocatalytic activity of various materials such as metals, metal oxides, alloys, complexes, and carbon (Taha et al.
, 2.
In electrochemical biosensors, electrodes play an essential role in signal transmission.
Carbon electrodes are often chosen because of their wide potential range, inert, low background current, and affordable price (Gaffar et , 2.
Although Au.
Ag, and Pt electrodes are used in some electrochemical sensor experiments, they are relatively expensive (Mahajan et al.
, 2.
Glassy Carbon Electrode (GCE) has outstanding characteristics that Cite this as: Gunawan.
Hardian.
, and Murniati.
, 2025.
Cyclic Voltammetry Study of the Influence of Concentration of K3[Fe(CN).
and Glucose on Glassy Carbon Electrode.
ALCHEMY Jurnal Penelitian Kimia, 21.
, 43-52.
https://dx.
org/10.
20961/alchemy.
Copyright A 2025.
Universitas Sebelas Maret.
ISSN 1412-4092, e ISSN 2443-4183 Gunawan et al.
ALCHEMY Jurnal Penelitian Kimia.
Vol.
2025, 43-52
are suitable for electrochemical applications.
It has high electrical conductivity, wide potential range, high hardness, chemical stability, inert properties, and affordability.
Additionally, it has high purity, dense pore volume, and a large surface area (Abdel-Aziz et al.
, 2022.
EL-Deeb et al.
, 2.
Cyclic voltammetry is an electrochemical method to study redox characteristics.
This method applies a voltage to the electrodes, and the resulting current is measured (Venton and Cao, 2.
A voltammogram is a graph that shows the relationship between the measured current and the potential generated during cyclic voltammetry, which starts from the initial potential and returns to the initial potential (Wahyuni et al.
, 2.
This method is often used to study the reversible electron transfer capability in the redox reactions monitored through cyclic voltammograms, depicting the current and potential (Herbei et al.
, 2.
Cyclic voltammetry can be used to measure parameters such as half-wave potential, electron transfer coefficient, and concentration of redox species in solution, as well as to provide information on redox reaction kinetics, electrochemical properties of compounds, and identification of redox species in solution (Wang et al.
, 2.
Understanding the effect of KCE[Fe(CN)CI] and glucose concentrations on GCE is crucial for developing This is because the KCE[Fe(CN)CI] standard solution is commonly used in electrochemical studies due to its accessibility, low cost, stability in electron transfer, good diffusion capabilities, and its ability to be used at various concentrations (Koy et al.
, 2.
Therefore, understanding the effect of concentration variation can contribute to ensuring the optimal performance of GCE in real-world applications.
Additionally, glucose is a highly important analyte for biomedical and industrial applications, especially for non-enzymatic glucose sensors.
Understanding how glucose concentration affects electrode performance facilitates improved sensor calibration, leading to more sensitive and accurate glucose detection.
This is essential for developing reliable glucose biosensors, which are widely used in healthcare for monitoring blood glucose levels in diabetic patients (Mousavi et al.
, 2.
Most of the working electrodes used were modified, as conducted by Abdel-Aziz et al.
and Chen et .
Using a commercial GCE, this study investigated how variations in the concentrations of KCE[Fe(CN)CI] and glucose affect the performance of GCE using cyclic voltammetry.
This study focused on how concentration variations influence the redox process.
The results confidently will significantly contribute to the optimization of non-enzymatic biosensors for glucose detection.
In addition, this study aims to enhance the sensitivity and accuracy of biosensors, especially for applications in the medical and industrial fields.
RESEARCH METHODS
Materials The chemicals used in this research were pro-analysis .
) from Merck: potassium chloride (KC.
, potassium ferricyanide K3[Fe(CN).
, sodium hydroxide (NaOH), glucose, and distilled water.
The equipment used included standard glassware in the chemistry laboratory.
The cyclic voltammetry setup involved a mini electrolysis cell .
mL) equipped with three electrodes .
ach diameter= 0.
5 m.
, a platinum (P.
auxiliary electrode, a glassy carbon (GC) working electrode, and an Ag/AgCl reference electrode.
For instrumentation, an INGSENSTM Electrochemical Workstation potentiostat type 1030 was used, equipped with a connecting cable to connect to a computer to respond to real-time cyclic voltammogram results.
Data was processed using Microsoft Excel and Origin Pro-lab software program version 2019.
Electrode Preparation The GCE surface was rinsed with acetone and distilled water and then dried.
The Pt electrode was also rinsed with distilled water thoroughly on its surface and dried.
Next, each electrode was cleaned using ultrasonic cleaner in distilled water for 15 minutes to ensure complete removal of surface contaminants.
The Ag/AgCl electrodes were rinsed with distilled water and dried.
The electrodes used in this study are shown in Figure 1.
Copyright A 2025.
Universitas Sebelas Maret.
ISSN 1412-4092, e ISSN 2443-4183 Gunawan et al.
ALCHEMY Jurnal Penelitian Kimia.
Vol.
2025, 43-52
Figure 1.
Glassy carbon working electrode (GCE), .
Platinum (P.
auxiliary electrode, dan .
Ag/AgCl reference electrode.
Characterization of Glassy Carbon Electrode with K3[Fe(CN).
Solution A series of electrochemical instrumentation consisting of a potentiostat connected to software was used to perform cyclic voltammetry measurements.
This system utilized three electrode systems: GCE as the working electrode.
Pt electrode as the auxiliary electrode, and Ag/AgCl electrode as the reference electrode.
The research analyzed K3[Fe(CN).
solution with five concentration variations, 1 to 5 mM in 0.
2 M KCl solution.
Cyclic voltammograms were recorded at different scanning speeds of 25, 50, 75, and 100 mV/s within a potential range 5 Ae 1 V.
Performance of Glassy Carbon Electrode in Glucose Solution Using the same electrochemical system, the analyte solution was glucose solution with concentration variations of 1 Ae 5 mM in 0.
1 M NaOH solution.
The scanning speeds used were 50, 100, 150, 200, 250, and 300 mV/s in the potential range between -10 and 10 V.
In addition, 10 scanning cycles were performed at a concentration of 5 mM to verify the electrodes' stability and determine the amount of error in the measurements.
RESULTS AND DISCUSSION
Characterization of Glassy Carbon Electrode With K3[Fe(CN).
Solution The characteristics of the cyclic voltammogram have been studied based on a three-electrode system of cyclic voltammetry measurement, including a working electrode for the redox reaction site, a reference electrode that regulates the potential range, and an auxiliary electrode to conduct the current flowing during the redox chemical process on the surface (Cakici et al.
, 2.
Before use, the electrode was initially cleaned using a cloth to clean the electrode (Puthongkham and Venton, 2.
Furthermore, the electrode was cleaned again using an ultrasonic cleaner to clean and remove dirt or disturbing substances.
In this study, the measurement process of one unit of cyclic voltammetry is illustrated in (Figure .
Figure 2.
The electrochemical cell, .
INGSENSTM potentiostat apparatus, and .
A computer unit with data In cyclic voltammetry measurements for electrode characterization.
K3[Fe(CN).
solution was used because it has a fast electron transfer reaction, making it suitable as a standard solution for electrode calibration and Copyright A 2025.
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ISSN 1412-4092, e ISSN 2443-4183 Gunawan et al.
ALCHEMY Jurnal Penelitian Kimia.
Vol.
2025, 43-52
produces electrochemical processes that are reversible and have stable redox properties (Pastor et al.
, 2.
The measurements were initiated with a 1mM K3[Fe(CN).
solution in 0.
2 M KCl with scan rates of 25, 50, 75, and 100 mV/s and the potential given between -1.
5 to 1 V (Figure .
Based on the measurement results, several key parameters were identified, namely peak potential (Epc.
Ep.
and peak current .
pa, ip.
in the cyclic voltammogram (Elgrishi et al.
, 2.
Figure 3.
Cyclic voltammogram profile of K3[Fe(CN).
1mM solution in 0.
2M KCl solution, at 25, 50, 75, 100 mV/s scan rates.
During the measurement process, a redox chemical reaction occurred, producing anodic peak current .
pa and cathodic peak current (Ip.
values observed at the optimal scan rate of 75 mV/s with a ratio of ipa/ipc = 0.
99 (Table The ipa/ipc ratio value close to 1 indicated that the redox process is reversible from Fe2 to Fe3 .
Therefore, a scan rate of 75 mV/s was chosen for the subsequent measurement.
The fast scan rate formed a thin diffusion layer, making electron transfer around the electrode surface more A scan rate of 100 mV/s was previously attained for the Fe2 /Fe3 system using a polypyrrole/polyphenol oxidase-modified Pt electrode (Murniati et al.
, 2012.
and a polypyrrole/polyphenol oxidase-modified steel gauze electrode (Murniati et al.
, 2012.
Based on the research by Chen et al.
, the electrochemical sensor constructed through the process of electropolymerization (EP) of -cyclodextrin on a glassy carbon electrode (CDP/GCE) attained a consistent scan rate of 100 mV/s.
Table 1.
ipa/ipc measurement results of 1mM K3[Fe(CN).
solution in 0.
2M KCl solution at scan rates of 25, 50, 75, 100mV/s.
Scan rate Epa Epc .
V) ipa .
A) ipc .
A) iEP= E0= (Epa Ep.
/2 ipa/ipc (Mv/.
V) Epa-Epc .
V) 20 y 10-5 8.
62 y 10-6 54 y 10-5 1.
41 y 10-5 95 y 10-5 1.
96 y 10-5 17 y 10-5 1.
78 y 10-5 In the previous study, tests on KCE[Fe(CN)CI] were conducted at concentrations of 5 Ae 10 mM, showing relatively high sensitivity (Radhi and Al-Mulla, 2.
Another study also measured 5 mM KCE[Fe(CN)CI] using a commercial Screen-Printed Carbon Electrode (SPCE), which resulted in an oxidation current of 19.
(Wahyuni et al.
, 2.
However, neither study explained the effect of these concentration variations.
Therefore, subsequent measurements were performed using KCE[Fe(CN)CI] analyte solution with varying 1 Ae 5 mM concentrations, tested in a 0.
2 M KCl solution.
The measurements were carried out using an optimum scan rate of 75mV/s and a potential range of -1.
5 to 1 V, as shown in Figure 4.
The results of the cyclic voltammograms profile in Figure 4 showed that the highest peak was observed at 5 mM K3[Fe(CN).
This is consistent with Faraday's law, which postulates that the current generated by an electrochemical cell is directly proportional to the concentration of the solution used.
This study expects diffusion currents to occur during redox at the electrode surface in the anodic current from Fe 2 to Fe3 .
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ISSN 1412-4092, e ISSN 2443-4183 Gunawan et al.
ALCHEMY Jurnal Penelitian Kimia.
Vol.
2025, 43-52
Figure 4.
Cyclic voltammogram profiles of K3[Fe(CN).
1 Ae 5 mM solutions in 0.
2 M KCl solution at a scan rate of 75mV/s.
The diffusion process causes this phenomenon in an electrolyte phase solution where particles migrate from high to low concentrations (Joshi.
and Sutrave, 2.
However, special attention was also paid to the ipa/ipc ratio value close to 1, which was observed at 1 mM concentration with ipa/ipc = 0.
99, as noted in Table 2.
To further quantify this trend.
Table 2 presents a detailed comparison of peak potential (E pa.
Ep.
, peak current .
pa and ip.
, and the ipa/ipc ratio at different scan rates.
Table 2.
The ipa/ipc measurement results of 1 Ae 5 mM K3[Fe(CN).
solution in 0.
2 M KCl solution at scan rates of 25, 50, 75, 100 mV/s.
Concentration Epa Epc ipa .
A) ipc .
A) iEP= E0= (Epa Ep.
/2 ipa/ipc .
M) .
V) .
V) Epa-Epc .
V) 95 y 10-5 1.
96 y 10-5 17 y 10-5 2.
98 y 10-5 36 y 10-5 3.
01 y 10-5 59 y 10-5 4.
83 y 10-5 24 y 10-5 5.
91 y 10-5 The uses of different K3[Fe(CN).
concentration variations in 0.
2 M KCl aim to ensure the stability of the commercial GC working electrode so that it can work optimally during the redox process.
The redox reaction in the KCE[Fe(CN)CI] system follows Equations 1 and 2.
Reduction: Fe(CN)63- .
e- .
Ie Fe(CN)64- .
Oxidation: Fe(CN)64- .
Ie Fe(CN)63- .
e- .
Figure 5 shows the results of variations in the concentration of K 3[Fe(CN).
from 1 to 5 mM solution in 0.
KCl solution with a regression value close to 1.
This indicates that the Fe 2 to Fe3 redox reaction that occurs is E-04 Ipa Ipc y = 1E-05x 8E-06 RA = 0.
I .
A) E-05
E 00
E-05
E-04
y = -1E-05x - 6E-06 RA = 0.
K3[Fe(CN).
Standard Solution .
M) Figure 5.
Linear ipa-ipc curves of varying concentrations of K3[Fe(CN).
Performance of Glassy Carbon Electrode In Glucose Solution Previous non-enzymatic glucose testing was conducted with concentrations of 0 Ae 1.
5 mM in 0.
1 M NaOH using a scan rate of 100mV/s on a GC working electrode modified with copper sulfide using chitosan, nafion, and Copyright A 2025.
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Vol.
2025, 43-52
PVP polymers, yielding the highest current peak at a concentration of 1.
5 mM (Mazurkyw et al.
, 2.
The experiment used a 1 mM glucose in 0.
1 M NaOH solution, with varying scan rates of 50, 100, 150, 200, 250, and 300 mV/s, and a potential range of -10 to 10 V.
The measurement data are presented in Figure 6.
Figure 6c, shows that the measurements commence with the highest scan rate and decrease to the lowest, while the potential increases from the lowest to the highest value.
This methodology is intended to enhance the redox process, as indicated by the differences in oxidation and glucose reduction peak heights at various scan rates.
The measurement data are presented in Table 3.
Figure 6.
Cyclic voltammogram profile of NaOH solution, .
Cyclic voltammogram profile of glucose solution, and .
Cyclic voltammogram profile of 1mM glucose solution in 0.
1 M NaOH solution, at scan rates of 50, 100, 150, 200, 250, 300 mV/s.
Table 3.
ipa/ipc measurement results of 1mM glucose solution in 0.
2 M NaOH solution at scan rates of 25, 50, 75, and 100 mV/s.
Scan rate Epa Epc .
V) ipa .
A) ipc .
A) iEP= E0= (Epa Ep.
/2 ipa/ipc (Mv/.
V) Epa-Epc .
V) 38 y 10-5 -1.
84 y 10-5 65 y 10-5 -4.
19 y 10-5 68 y 10-5 -5.
61 y 10-5 69 y 10-5 -3.
66 y 10-5 71 y 10-5 -6.
15 y 10-5 99 y 10-5 -6.
27 y 10-5 The data from Table 3 and the information illustrated in Figure 7 indicate that the optimal scan rate is 200 mV/s, with an ipa/ipc ratio of 1.
At this scan rate, the reduction and oxidation processes are balanced.
The peak current increases with the scan rate.
However, an excessively high scan rate can result in an insufficiently thin diffusion layer, hindering electron transfer and preventing full oxidation of the analyte.
Conversely, a scan rate Copyright A 2025.
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that is too low leads to the formation of a diffusion layer that also inhibits electron transfer (Irdhawati et al.
, 2.
Therefore, a scan rate of 200 mV/s is recommended.
IpA/IpC IpC/IpA ipa-ipc Ratio Scan Rate .
V/.
Figure 7.
Comparison of ipa-ipc spots from various scan rates.
Subsequent measurements were performed using glucose analyte solutions with varying concentrations ranging from 1 to 5 mM tested in 0.
1 M NaOH solution.
Measurements were performed with an optimum scan rate of 200 mV/s and a potential range from -10 to 10 V.
The measurement results are presented in (Figure 8.
Figure 8a and Table 4, it can be seen that the oxidation peak reaches the highest value at 5 mM concentration.
This is due to the involvement of more electroactive species at higher concentrations.
Ipa
E-04
y = 1E-05x 2E-05 RA = 0.
E-04
ipa/ipc Ratio
Ipc
E-05
E 00
E-05
E-04
y = -9E-06x - 3E-05 RA = 0.
Glucose .
M) in 0.
1 M NaOH .
Figure 8.
Cyclic voltammogram profiles of 1 to 5 mM in 0.
1 M NaOH solution at a scan rate of 200 mV/s dan .
Linear curve of ipa/ipc vs varying glucose concentration in 0.
1 M NaOH.
Additionally, as shown in Figure 8b, linear regression calculations were performed for the anodic and cathodic peaks relative to the glucose solution.
The linear correlation obtained for the anodic peak .
was R = 8064, indicating a more stable response than the cathodic peak .
, which correlated with R = 0.
This suggests that the predominant reaction is anodic or oxidative.
Furthermore.
Table 4 demonstrates that the measurement results for ipa exhibited a stable increase from the lowest to the highest glucose concentration, while ipc displays an unstable trend.
Table 4.
ipa and ipc data of analyte solutions of concentration variation 1 Ae 5 mM in 0.
1 M NaOH solution.
Concentration .
M) ipa (A) ipc (A) Ratio .
pa/ip.
69 y 10-5 66 y 10-5 23 y 10-5 78 y 10-5 92 y 10-5 58 y 10-5 05 y 10-5 93 y 10-5 42 y 10-5 76 y 10-5 The following reaction equations characterize the oxidation and reduction processes in glucose solution, as described in Equations 3 and 4.
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Oxidation: C6H12O6 2OHOe Ie C6H10O6 2eOe 2H2O Reduction: 2OH IeH2O O2 2e The measurement of a 5 mM glucose solution using GCE was performed with 10 repetitions, with the cyclic voltammogram over 10 cycles shown in Figure 9.
Figure 9.
Repeatability cyclic voltammogram profile of 10 cycles of 5 mM glucose solution in 0.
1 M NaOH solution with a scan rate of 300 mV/s.
According to Table 5, the average values were ipa = 4.
86 y 10-5 A 3.
23 y 10-6 and ipc = -4.
83 y10-5 A 2.
56 y 10-6, with ipa/ ipc = (-1.
A 0.
These results indicate relatively stable and precise standard deviations for measuring 5 mM glucose in 0.
1M NaOH over 10 cycles on the GCE.
Table 5.
Repeatability measurement data.
Repetition 42 y 10-5 14 y 10-5 77 y 10-5 19 y 10-5 86 y 10-5 08 y 10-5 50 y 10-5 68 y 10-5 56 y 10-5 36 y 10-5 Mean 85 y 10-5 Standard deviation 23 y 10-5 33 y 10-5 07 y 10-5 20 y 10-5 02 y 10-5 93 y 10-5 95 y 10-5 78 y 10-5 71 y 10-5 68 y 10-5 62 y 10-5 82 y 10-5 55 y 10-5 Ratio .
pa/ip.
CONCLUSION This study found that a concentration of 1mM KCE[Fe(CN)CI] and glucose provided an ipa/ipc ratio close to 1, indicating a stable and reversible redox process.
On the other hand, a concentration of 5 mM produced the highest peak current, indicating higher sensitivity.
Therefore, a concentration of 1 mM is optimal for redox stability, while a concentration of 5 mM is best for increasing sensitivity.
CONFLICT OF INTEREST
There is no conflict of interest in this article.
AUTHOR CONTRIBUTION
AM: Conceptualization.
Methodology.
Supervision.
Manuscript Review, and Editing.
AFG: Data Analysis.
Manuscript Drafting.
AH: Supervision.
Manuscript Review, and Editing.
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ALCHEMY Jurnal Penelitian Kimia.
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ACKNOWLEDGEMENT
This research was supported by the Ministry of Research.
Technology and Higher Education of the Republic Indonesia (DRTPM-PTKN:
156/ES/PG.
PT/2024.
093/SP2H/RT-MONO/LL4/2024.
SPK/008/LPPM/VII/UNJANI for the AM Research Grou.
REFERENCES