Sensitive and Selective Electrochemical Sensor for Antimony Using Boron-doped Diamond Nanoparticles

At a Glance

Metadata	Details
Publication Date	2023-12-18
Journal	Sensors and Materials
Authors	Prastika Krisma Jiwanti, Moh. Agus Rismafullah, Aning Purwaningsih, Md. Shalauddin, Shamima Akhter
Institutions	Airlangga University, University of Malaya
Citations	7
Analysis	Full AI Review Included

Executive Summary

This analysis outlines the development and performance of a highly sensitive and selective electrochemical sensor for Antimony (Sb³⁺) utilizing Boron-doped Diamond Nanoparticles (BDDNPs) modified on a Screen-Printed Electrode (SPDE).

Core Innovation: A cost-effective, portable SPDE modified with BDDNPs, leveraging the wide potential window and low background current of BDD for enhanced electroanalytical performance.
High Sensitivity: The sensor achieved a low Limit of Detection (LOD) of 2.41 x 10^-8 M for Sb³⁺ using Square Wave Voltammetry (SWV).
Analytical Performance: The sensitivity was determined to be 29.18 µA/µM, with a wide linear concentration range spanning 0.19 to 0.59 µM.
Mechanism: The BDDNP modification increases the electrode surface area and active sites, promoting faster ion diffusion and greater adsorption of the Sb³⁺ reduction product.
Selectivity and Stability: The SPDE demonstrated excellent selectivity, successfully detecting Sb³⁺ in the presence of common interferents (Cd²⁺, Fe³⁺, Co²⁺, Pb²⁺), and showed long-term stability.
Real-World Application: The method was successfully applied to the determination of Sb³⁺ in river water samples, yielding high recovery rates (102-107%).

Technical Specifications

Parameter	Value	Unit	Context
Analyte LOD	2.41 x 10^-8	M	Limit of Detection (SWV, SPDE)
Sensitivity	29.18	µA/µM	Gradient of calibration graph
Linear Range	0.19 to 0.59	µM	Sb³⁺ concentration range
Optimized pH	4.5	-	Acetate buffer supporting electrolyte
SWV Amplitude	0.05	V	Optimized electrochemical parameter
SWV Frequency	50	Hz	Optimized electrochemical parameter
SWV E-step	0.05	V	Optimized electrochemical parameter
BDDNP Size Range	0 to 250	nm	Purchased material specification
Average SPDE Size	192.22	nm	Determined via ImageJ analysis of FESEM
B-C Vibration Peak	1438	cm^-1	FTIR spectrum (Substitutional boron)
BDD Lattice Planes (XRD)	(111) and (220)	-	Confirmed by peaks at 43°, 85°, 75°, 36°
UV-Vis Absorption Peak	242	nm	Corresponds to electronic transition of boron
River Water Recovery	102 to 107	%	Accuracy test using spiked samples
Relative Standard Deviation (RSD)	< 5	%	Precision requirement for high-performance sensor

Key Methodologies

The sensor fabrication and analysis relied on precise material preparation and optimized electrochemical techniques:

BDDNP Ink Preparation:
- Recipe: 10 mg of BDDNPs (0-250 nm size) mixed into 0.5 mL of 30% ethanol.
- Dispersion: Ultrasonication was used until the BDDNPs were completely dispersed.
SPDE Modification:
- Method: Drop-casting 20 µL of the BDDNP ink suspension onto the working electrode (WE) surface of the commercial Screen-Printed Electrode (SPE).
- Curing: The modified electrode was dried in an oven at 60 °C for 90 minutes to evaporate the solvent and prevent leaching.
Electrochemical Measurement (SWV):
- Electrolyte: 0.1 M acetate buffer solution, optimized at pH 4.5.
- Sample Preparation: 1.33 µL of 60 µM Sb³⁺ solution was mixed with 60 µL of the buffer and drop-cast onto the SPDE.
- Procedure: A 5-second equilibration period was followed by scanning the potential from -1 V to 1 V.
- Optimized Parameters: Amplitude 0.05 V, Frequency 50 Hz, E-step 0.05 V.
Material Characterization:
- Surface Morphology: Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy-Dispersive X-ray (EDX) spectroscopy.
- Crystallinity: X-ray Diffraction (XRD) confirmed the diamond lattice planes (111) and (220).
- Chemical Structure: Fourier Transform Infrared Spectroscopy (FTIR) identified B-C (1438 cm^-1) and B-O (1092 cm^-1) species.
- Electronic Properties: UV-Vis spectroscopy confirmed boron electronic transitions at 242 nm.

Commercial Applications

The BDDNP-modified SPDE technology is highly relevant for applications requiring robust, portable, and sensitive trace metal detection, leveraging the inherent stability of boron-doped diamond materials.

Environmental Monitoring: Rapid, in situ detection of toxic heavy metal ions (specifically Sb³⁺) in fresh water sources, rivers, and groundwater, replacing complex, time-consuming laboratory techniques (spectroscopy, chromatography).
Water Treatment and Safety: Monitoring effluent streams from industrial processes (e.g., glass, textile, pigment manufacturing) to ensure compliance with regulatory limits for antimony.
Food and Beverage Industry: Trace analysis of antimony leaching from polyethylene terephthalate (PET) packaging used for alcoholic and nonalcoholic beverages, where Sb is commonly used as a polymerization catalyst.
Portable Analytical Devices: Integration into handheld electrochemical analyzers (like the PalmSens used in the study) for field-deployable, high-performance sensing kits.
Diamond Electrochemistry Products: The technology validates the use of BDDNPs as superior electrode modifiers, applicable to developing sensors for a wide range of analytes beyond Sb³⁺, including other heavy metals and organic pollutants.

View Original Abstract

In this study, boron-doped diamond nanoparticles modified on the surface of a screen-printed electrode (SPE) were prepared for the sensitive and selective determination of Sb 3+ using square wave voltammetry.The effect of electrochemical parameters such as the type of supporting electrolyte, pH, signal per background, and scan rate on the sensitivity of the sensor for the detection of Sb 3+ was investigated.Under optimized conditions with an amplitude of 0.05 V, a frequency of 50 Hz, and an E-step of 0.05 V, the square wave voltammogram between -1.0 and 1.0 V gave a limit of detection of 2.41 × 10 -8 M for an Sb 3+ concentration range from 0.19 to 0.59 μM.The method was used to determine Sb 3+ ions in river water with satisfactory results.The modified electrode displayed benefits such as high sensitivity and selectivity, long-term stability, easy preparation, and wide linear range.

Tech Support

Original Source

DOI: https://doi.org/10.18494/sam4599