Gunshot Residue Research Articles

Development of a Dimensional Analysis Approach in Gunshot Residue Images Using Computerized Image Processing

Computer image processing is a method that uses artificial intelligence and machine learning-based general learning algorithms. With this method, objects in digital images (photos or videos) can be grouped by being perceived and detected. Computerized image processing method can be applied to almost all kinds of digital data produced with the developing technology. Nowadays, the identification and detection of gunshot residues (GSR) can be done manually by experts from the acquired images. In this study, computerized image processing method was used for the identification and dimensional analysis of gunshot residues (GSR). In this new proposed method, a dataset of 18500 digital image samples obtained from three different caliber cartridges (MKE, Gecco and S&B brands) was used. From the results of the study, it has been shown that the Computer Vision Method is a successful method in the automatic dimensional classification of GSRs.

Voltammetric analysis of luminescent markers in gunshot residues.

Currently, SEM-EDS is used to detect gunshot residue (GSR) from the presence of Ba, Pb, and Sb in the sample. However, the development of new nontoxic ammunition (NTA) has prevented conventional metals from being found. In this work, we aim to determine the presence of an inorganic luminescent chemical marker based on rare earth in gunshot residues using the technique of squarewave voltammetry (SWV). After firing, the luminescent complex [(Eu2 Zr)(btc)3 (Hbtc)0.5 .6H2 O], which is used as a chemical marker, can be detected under a UV lamp. An aqueous solution with 0.1mol L-1 KCl as supporting electrolyte can be easily collected on carbon paste electrode surfaces for SWV analysis A=100 mV, f=10Hz, and step potential of 5mV are required. The luminescent marker incorporated into the carbon paste electrode showed two anodic peak currents in the region of 0.4V (vs Ag/AgCl) and at 0.75 V (vs Ag/AgCl) and also a cathodic one in 0.4V (vs Ag/AgCl). SEM-EDS was able to analyze the same voltammetric results for conventional and nontoxic ammunition containing the luminescent marker. Therefore, voltammetry and SEM-EDS are valid for detecting the new residue marker in GSR. Despite this, the electrochemical method is still more advantageous because of its low cost and lack of expensive equipment and supplies in forensic laboratories.

The Nanoforensic: An Advanced Perspective in Crime Investigation

Nano forensics is the advanced application of nanotechnology-based techniques to resolve cases in forensic science. Forensic science offers scientific methods in a criminal investigation. Nano-forensics deals with the development of new approaches for fingerprint visualization, DNA isolation, forensic toxicology, explosive detection, identification of body fluids, gunshot residue analysis, detection of illicit drugs, etc. The nanomaterials used in forensic science are nanocrystals, nanoparticles, quantum dots, nanobelts, nanocomposites, nanoclusters, nanotubes, nanorods, etc. The scope of nanotechnology is very wide.

Divergent gunshot residues and characterization of the memory effect in a .22 caliber revolver and pistol

BackgroundThe forms and compositions of primer gunshot residue (GSR) in shooting cases have been routinely analyzed in many crime labs by scanning electron microscope/energy-dispersive X-ray spectroscopy (SEM/EDS). Gunshot residue studies over the last 30 years have identified a contribution by residual GSR from surfaces within the firearm to GSR (the “memory effect”). In this study, we first focus on the GSR compositional differences between target, bore, and cylinder gap for a .22 caliber revolver which has received little attention in the literature. Secondly, we examine the behavior of elements involved in the residual contribution to GSR for a .22 caliber pistol.ResultsThe compositions of target, bore, and cylinder gap GSRs from a .22 caliber revolver were determined for 11 discharge series. Breech GSR compositions from a .22 caliber pistol changed in sequential discharges revealing behavior of individual primer and bullet elements. The target GSR forms from some .22 caliber ammunitions were not spherical.ConclusionsFor the revolver, GSR compositions from the target, bore, and cylinder gap are divergent. Analysis of the pistol’s breech GSRs indicated mixing with the previously deposited GSRs resulting in a sequential contribution or loss of elements and redeposition of the new composition. Aluminum did not contribute to the residual GSR. The GSR composition of a discharge and its contribution to residual GSR on the internal parts of the firearm represents a complex process which likely involves a number of variables including, but not restricted to firearm design, primer composition, pressure and temperature of the discharge gas, and bullet surface composition.

A face oculta das cenas de crime: uma revisão sobre microvestígios

Introduction: Microtrace consists of materials of different nature that can be found in crime scenes, being difficult to see with the naked eye, due to their submillimetre, submicroscopic or microscopic dimensions. Objectives: This work aimed to address the characteristics of the main types of microtrace found in crime scenes. Material and Methods: As a research methodology, publications exclusively in the format of scientific articles were sought, indexed in the Web of Science and ScienceDirect databases, using the terms microtrace and trace evidence. Results: Microtrace are classified according to their organic origin (fingerprints, diesel and biodiesel, hair, wood, microscopic plant origin and natural fibres), natural inorganic (microfossils, minerals and soils) and anthropic inorganic (bricks, paints, glass, plastics, synthetic fibres, gunshot residue and paper), and can reveal crucial information at crime scenes, depending on the technique used to process it (e.g., inductively coupled plasma, infrared spectroscopy, gas and liquid chromatography, micro Raman spectroscopy). In this way, laboratories must meet specific requirements, regardless of the analytical technique to be used, to extract reliable information from microtrace. These requirements consist of: 1) Accuracy, 2) Sensitivity, 3) Uniqueness, 4) Association, 5) Speed and simplicity, 6) Versatility, 7) Reliability and reproducibility, 8) Traceability, 9) Accessibility, and 10) Availability of data. Conclusions: This work highlighted the diversity and importance of microtrace, since extracting information from them can give them great potential as material evidence in criminal investigations, depending on the applied collection methods and the techniques used in their laboratory examination.

Lead isotope measurement of primer gunshot residues and likelihood ratio predictions for forensic cartridge discrimination and individualization in China

Gunshot residues (GSR), cartridge projectiles, and casings are frequently encountered evidence in gun-related forensic investigations. However, in circumstances where the investigation of striation marks is impossible, such as unrecovered or deformed projectiles and cartridge casings, GSR deposited on the hands or clothes of the shooter and victim-related items can provide information to establish a link between the suspect, the firearms used, and the victim. Since the formula of primers used by all cartridge manufacturers in China is identical, links based on the conventional morphological and compositional analysis of GSR are difficult to establish. However, the abundance of lead isotopes in primer components of lead styphnate varies significantly, and a fundamental understanding of these differences may facilitate the validation of primer (p)GSR evidence in forensic investigations. Here, 44 pGSR samples were characterized by Pb isotope ratios of 206 Pb/204 Pb, 207 Pb/204 Pb, and 208 Pb/204 Pb using laser ablation multicollector inductively coupled plasma mass spectrometry. There was no obvious mass fractionation of the lead isotope ratios of the primers from individual cartridges analyzed before and after the shooting process, thereby establishing a basis for the comparison of pGSR and unfired cartridges. Evaluation of the results using univariate likelihood ratio (LR) computations revealed low rates of misleading evidence (<0.53%) The results demonstrated that lead isotope ratio analysis of pGSR and LR predictions can provide a practicable method for forensic cartridge discrimination and individualization.

Two highly photoluminescent Eu3+ β-diketonates complexes with ε-caprolactam as ancillary ligands: From synthesis to the first example as gunshot residue markers

This study reports the synthesis of two new Eu3+ β-diketonates and their complete experimental and theoretical spectroscopic characterizations. These compounds present [Eu(tta)3(ε-cap)(H2O)] 1 and [Eu(btfa)3(ε-cap)(H2O)] 2, supported by 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (Htta), 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbtfa) formulas with a ε-caprolactam molecule acting as an ancillary ligand. These ligands act as efficient sensitizers for the Eu3+ ion, giving rise to an intense red emission. Due to this intense luminescence, compounds [Eu(tta)3(e-cap)(H2O)] 1 and [Eu(btfa)3(e-cap)(H2O)] 2 were selected as markers for the ammunition of a 38-caliber revolver and 0.380 pistol, respectively. This application is unprecedented for Eu3+ β-diketonates. The forensic assays indicated evident formation of luminescent gunshot residues (LGSR). Thus, these compounds may play an efficient role as allies in elucidating crimes.

Should inorganic or organic gunshot residues be analysed first?

Gunshot residues (GSR) collected during the investigation of firearm-related incidents can provide useful information for the reconstruction of the events. Two main types of GSR traces can be targeted by forensic scientists, the inorganic (IGSR) and the organic GSR (OGSR). Up to now, forensic laboratories have mainly focused on the detection of inorganic particles on the hands and clothes of a person of interest using carbon stubs analysed by scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM/EDS). Several approaches have been proposed to also analyse the organic compounds since they might bring additional information for the investigation. However, implementing such approaches might disrupt the detection of IGSR (and vice versa depending on the applied sequence of analysis). In this work, two sequences were compared for the combined detection of both types of residues. One carbon stub was used for collection, and the analysis was performed either by targeting the IGSR or the OGSR first. The aim was to evaluate which one allows maximum recovery of both types of GSR while minimising losses that might occur at different stages of the analysis process. SEM/EDS was used for the detection of IGSR particles while an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was used for the analysis of OGSR compounds. Extracting OGSR first required the implementation of an extraction protocol that did not interfere with the IGSR particles present on the stub. Both sequences allowed good recovery of the inorganic particles since no significant difference was observed in the detected concentrations. However, OGSR concentrations were lower after IGSR analysis than before for two compounds (ethyl and methylcentralite). Thus, it is advised to extract rapidly the OGSR before or after IGSR analysis to avoid losses during the storage and analysis processes. The data also indicated that there was a low correlation between IGSR and OGSR highlighting the potential of a combined detection and analysis of both types of GSR.

Identification and highly selective differentiation of organic gunshot residues utilizing their elemental and molecular signatures

Firearm related evidence is of great significance to forensic science. In recent years, many researchers have focused on exploring the probative value of organic gunshot residue (OGSR) evidence, which is often bolstered by many factors including recoverability. In addition, OGSR analysis has shown the potential to achieve differentiation between OGSRs generated from various ammunition brands and/or calibers. Raman spectroscopy is a vibrational spectroscopic technique which has been used in the past for gunshot residue analysis—including OGSR specifically. Raman spectroscopy is a nondestructive, highly-selective, simple, and rapid technique which provides molecular information about samples. LIBS or Laser-Induced Breakdown Spectroscopy is a simple, robust, and rapid analytical method which requires minimal to no sample preparation and a small amount of sample for analysis. LIBS provides information on the elemental compositions of samples.In this study, Raman spectroscopy and LIBS were used together in sequence in an attempt to achieve the specific identification and characterization of OGSR particles from ammunition types which were closely related. The main goal was to determine if this method had the potential to differentiate between various ammunition types of the same caliber and produced by the same manufacturer, and generated under identical firing conditions. High-resolution optical microscopy documented the OGSR particles’ morphologies and Raman spectroscopy was used to identify particles as OGSRs. Finally, LIBS analysis of the OGSR particles was carried out. Advanced chemometric techniques were shown to allow for very successful differentiation between the OGSR samples analyzed.

Evaluation of laser-induced breakdown spectroscopy (LIBS) applications in the aspect of forensic chemistry

The most common definition of forensic science is the application of science to solve legal cases. In order to establish or rule out a connection between a suspect and a crime scene, forensic scientists analyze evidence collected from the crime scene, using multidisciplinary scientific methods (physics, chemistry, biology, mathematics, medicine, psychology, sociology, etc.). The identification of the sample and determination of whether two or more objects share a similar origin have been accomplished in forensic science using a variety of analytical techniques from past to present. However nowadays, with the developing technology, new methods that are more sensitive and easy to use are preferred. One of these techniques is Laser-Induced Breakdown Spectroscopy (LIBS). In forensic studies, LIBS is used to examine materials like counterfeit money, drugs, explosives, fingerprints, gunshot residue, ink, paper, hair, paint, glass, etc. On the other hand, it is more useful method compared to other methods due to the absence or simplicity of sample preparation, easy to operate, allowing the analysis of major, minor or trace elements and giving rapid results. This paper presents a review of the application of LIBS in forensic chemistry and the analytical results obtained with LIBS.

Spectrophotometric Analysis of Nitrite in Gunshot Recentness Examinations from Non Toxic Ammunitions: Expanding the Frontiers of Forensic Chemistry

Nitrite ions consist on an important chemical clue related to gunshot examination, concerning to estimation of the time since discharge. Current forensic laboratory methods for nitrite analysis in gunshot residues are well established for investigating conventional ammunition residues. However, the use of these methods to analyze the so-called ecological or “non-toxic” ammunition has been less studied. Here, we have developed a spectrophotometric flow injection analysis method to test nitrite in samples of “non-toxic” ammunition residues. The ammunition used in these experiments was the NTA (non-toxic ammunition) model, .38 caliber, We also investigated the kinetics of nitrite decomposition for this type of ammunition over time. Sulfanilic acid and 1-naphthylethylenediamine in acetic acid were used as colorimetric reagents. The linear dependence of the spectrophotometric signal on the nitrite concentration was as follows: A = 2.07 x 104 µmol-1 L [NO2-] + 6.78 x 10-3 with a correlation coefficient (r) of 0.9994. The standard deviation (SD) of the analytical curve was 3.17 x 10-3 resulting in a limit of detection (LOD) = 0.46 µmol L-1 and a limit of quantification (LOQ) = 1.56 µmol L-1. The proposed instrumental method was more sensitive than conventional colorimetric tests and permitted the detection window to be extended to 32 days while ensuring the safety and reliability required for forensic analysis, in comparison to 7-10 days usually proposed for conventional ammunition. Therefore, the proposed method can be safely employed in forensic laboratories for routine analysis of nitrite ions in GSR samples from ecological or “non-toxic” ammunition.

Distribution features of gunshot residue from hunting Steyr Mannlicher AUG-Z3 carbine on targets

To study the morphology of distribution of shot factors on white targets made of coarse calico at different distances. The study was conducted on 57 experimental damages of targets made of cotton fabric, caused by shots from hunting self-loading Steyr Mannlicher AUG-Z3 carbine of.223 Rem caliber. The number of experimental firings equal 19 was done by 3 shots at the distance from close range to 250 cm. The examination of shot targets was carried out using the visual, metric, stereoscopic (Leica 125M microscope) methods, in ultraviolet rays (LUMATEC SUPERLITE M Series light). The nature and morphology of distribution of gunshot residue on targets' surfaces made it possible to establish close range firing zones. The nature in which soot is deposited during shot under the conditions of point-blank range and in the first zone of close range (up to 8 cm) allows to establish the position of weapon's transverse plane relative to the target basing on a specific blowout of a gas-powder jet from special design of flame arrestor. The performed experimental shooting from hunting self-loading Steyr Mannlicher AUG-Z3 carbine made it possible to determine the metric and morphological characteristics of the close range firing zones: 1 zone is equal a distance up to 8 cm; 2 zone - up to 30 cm; 3 zone - up to 100 cm from muzzle of weapon. The design features of Steyr Mannlicher AUG-Z3 carbine's flame arrestor allow to identify the type of weapon according to the morphological pattern of target's damage. The complex of obtained data makes it possible to determine the firing distance with high accuracy.

A feasibility study of direct analysis in real time-mass spectrometry for screening organic gunshot residues from various substrates.

This study reports the use of direct analysis in real time-mass spectrometry (DART-MS) for the detection of organic gunshot residues (OGSR) in a variety of matrices of interest for forensics, customs, and homeland security. Detection limits ranged from (0.075 to 12) ng, with intra- and inter-day reproducibility below 0.0012% CV. The collection of mass spectra at multiple in-source collision-induced dissociation (is-CID) voltages produced distinctive mass spectral signatures with varying levels of fragmentation and allowed differentiation of isomers. To test method performance, a collection of 330 authentic specimens from various substrates were analyzed - (1) neat smokeless powders, (2) spent cartridge cases, (3) burnt particles removed from clothing via carbon stubs or (4) with tweezers, and hand samples from (5) non-shooters, and (6) shooters. A subset of hand specimens (n = 80) was further analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for confirmation and comparison. Seven types of ammunition from five manufacturers and two calibers were monitored for OGSR profiles with similar compositions observed for paired sets (e.g., unburnt smokeless powder and the respective residues on spent cartridges, clothing, and hands). No false positives were observed across all datasets. A 100% true positive rate (TPR) was observed for all substrates except the shooters' hands. Depending on the ammunition type and classification criteria, the shooters' hands exhibited a TPR ranging from 19% to 73%. The results show that DART-MS is feasible and versatile for fast screening of OGSR across various substrates but may benefit from alternative approaches to improve detection at trace levels.

Current approaches for sampling to study the traces of gunshot residue

An overview of researches, mainly by foreign specialists, on current available approaches for sampling to study the traces of gunshot residue (GSR) is presented. The comparative characteristics of traditional methods of samples (use of cotton and gauze tampons, blotting paper, textile fabrics, adhesive tapes, adhesives and vacuum samplers), as well as advanced technologies, including special devices and sorbents, are given. The characteristics of samplings from hands, scalp, nostrils, clothes of examined persons as well as procedures, that allow to increase the duration of GSR detection, are described in details. The importance of GSR sustainability over time is noted. On average, the most likely detection periods of particles are less than 1 hour for samples, collected from hands, more than 1 hour for samples from clothes and 2-3 hours for face. It is possible to detect the GSR particles in hair up to 24 h., and in nasal mucus after 6 h. of shot. The methods of identification and determination for analytes of inorganic and organic nature are discussed. The most common methods for determining heavy metal particles are atomic spectrometry, namely atomic absorption with electrothermal atomization and atomic emission. The combination of scanning laser ablation and mass-spectrometry with inductively coupled plasma makes it possible to detect more than 15 analytes in a single sample. Scanning electron microscopy with X-ray detectors is effective for the examination of powder particles. The described methods of sampling complement each other increasing the possibility of evidence base for court proceedings.

Hierarchical Modelling of Raman Spectroscopic Data Demonstrates the Potential for Manufacturer and Caliber Differentiation of Smokeless Powders

Gunshot residue (GSR) is an important type of forensic trace evidence produced when a firearm is discharged. Currently, inorganic GSR particles are used for establishing the fact of shooting. The organic gunshot residue (OGSR) has been recently shown to have great potential for providing additional information vital for the crime scene investigation. Smokeless powder is the precursor to OGSR and one of its chemical components. In this study, Raman spectroscopy and chemometric modeling were used to analyze smokeless powder extracted from ammunition cartridge cases. The proposed hierarchical model demonstrated great potential for determining the manufacture and the bullet type based on the analysis of smokeless powder. Expanding the developed approach to the analysis of OGSR will be needed to make it a useful tool for law enforcement agencies.

Validation of the Expert Methodology “Detection of Condensed Traces of Gunshot Residue Containing Heavy Metal Compounds on Various Objects by Scanning Electron Microscopy and X-Ray Microanalysis”

Validation of the Expert Methodology “Detection of Condensed Traces of Gunshot Residue Containing Heavy Metal Compounds on Various Objects by Scanning Electron Microscopy and X-Ray Microanalysis”

Elemental Characterization of Leaded and Lead-Free Inorganic Primer Gunshot Residue Standards Using Single Particle Inductively Coupled Plasma Time-of-Flight Mass Spectrometry.

This study describes the use of single particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOFMS) for the detection and classification of inorganic gunshot residue (IGSR) particles. To establish reliable multi-element criteria to classify IGSR particles, leaded and lead-free IGSR reference materials were analyzed, and the elemental compositions of the individual particles were quantified. The results suggest that expanded element compositions may be used to classify IGSR particles via spICP-TOFMS compared to those used in conventional IGSR analysis using scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS). For spICP-TOFMS analysis of leaded IGSR particles, classification may be based on the presence of lead (Pb), antimony (Sb), and barium (Ba) just as in SEM-EDS; however, additional particle types, such as lead-copper (Pb-Cu) particles, contribute significantly (∼30%) to the leaded IGSR particle population. In lead-free IGSR particles, the dominate multi-metal particle composition found is titanium-zinc (Ti-Zn) with a conserved Zn:Ti ratio of 1.4:1, but other elements, such as copper (Cu), are also characteristic. In mixtures of the two IGSR reference materials, we were able to classify over 80% of the multi-metal particles detected with no false-positive particle-type assignments. With spICP-TOFMS, particles smaller than those typically measured by SEM-EDS are detected, with estimated median diameters for leaded and lead-free IGSR of 180 and 320 nm, respectively. Through measuring these smaller particles, up to ∼two times more particles per mL are recorded by spICP-TOFMS compared to that found by SEM-EDS. Overall, high-sensitivity and high-throughput analysis using spICP-TOFMS enables quantitative, rapid multi-elemental characterization, and classification of individual IGSR particles.

Numerical Investigation on the Gas‐Solid Flow in Blast Flow Fields Induced by a High‐Speed Body

AbstractAs one of the critical phenomena during the firing of guns, propellant combustion creates an expanding gas plume with smoke containing the combustion residues. This paper aims to clarify the influence of gunshot residue particles on muzzle flow. Firstly, a two‐dimensional gas‐solid two‐phase model is established to describe the muzzle flow with gunshot residue for a small caliber rarefaction wave gun. And a discrete phase model is used to track particle trajectories for the dilute gas‐solid flow. Then the different development processes are discussed between the pure‐gas and the gas‐solid flow. Finally, the particle diameter and the mass fraction of particles are investigated to show the effects on the development process of the muzzle flow with gunshot resides. The results show that particles greatly influence the main flow parameters in the muzzle flow with gunshot residue. The gas velocity decreases due to the interaction between the particles and the gas. This paper provides a valuable reference for the study of muzzle flow.

Synthesis and Structural Characterization of an Amorphous and Photoluminescent Mixed Eu/Zr Coordination Compound, a Potential Marker for Gunshot Residues

Hydrogels based on mixed zirconium/europium ions and benzene tricarboxylic acid were synthesized by hydrothermal reaction. A solid glass-like material is formed upon drying, showing strong reddish luminescence. The system was characterized by solid-state nuclear magnetic resonance, thermal analyses, and infrared spectroscopy. The results reveal the amorphous character of the structure and the presence of at least four types of binding modes between the metal oxide clusters and benzene tricarboxylic acid. On the other hand, thermogravimetric analysis (TGA) showed high thermal stability, with the material decomposing at temperatures higher than 500 °C. The combination of intense Eu3+ luminescence with large thermal stability makes this material a strong candidate for application as a luminescent red marker for gunshot residue (GSR). As proof of concept, we show the feasibility of this application by performing shooting tests using our compound as a GSR marker. After the shots, the residual luminescent particles could be visualized in the triggered cartridge, inner the muzzle of the firearm, and a lower amount on the hands of the shooter, using a UV lamp (λ = 254 nm). Remarkably, our results also show that the Eu3+ emission for the GSR is very similar to that observed for the original solid material. These characteristics are of huge importance since they provide a chance to use smaller amounts of the marker in the ammunition, lowering the costs of potential industrial manufacturing processes.

New electrode material integrates silver nanoprisms with phosphorus-doped carbon nanotubes for forensic detection of nitrite

A screen-printed carbon electrode (SPCE) was modified with a nanohybrid of silver (Ag) nanoprisms and phosphorus (P)-doped carbon nanotubes (AgNPr@P-CNT). The modified SPCE was coupled with a simple, portable flow system to produce an efficient amperometric sensor for the detection of nitrite ion (NO2−). P-doped CNTs were prepared via a one-pot solvothermal method and the P-CNTs were decorated with Ag nanoprisms synthesized by a one-pot chemical reduction method. The as-prepared AgNPr@P-CNT nanohybrid was thoroughly characterized. Energy-dispersive x-ray (EDX) analysis, Fourier transform infra‐red (FTIR), and Raman spectroscopy results confirmed the successful doping of CNTs with P atoms. Transmission electron microscopy (TEM) revealed the decoration of P-CNTs with triangular Ag nanoprisms measuring 25 ± 7 nm. In the optimal condition, the flow injection-amperometric sensor based on the developed AgNPr@P-CNT/SPCE exhibited suitable electrocatalytic activity toward NO2− oxidation. As a result, NO2− was detected with high sensitivity (0.73 µA µM−1 cm−2), a wide linear range (0.010–4000 µM), and a low limit of detection (0.0032 µM). The proposed sensing system was successfully applied to detect NO2− in gunshot residue samples, achieving good recoveries. The advantages of the proposed AgNPr@P-CNT nanohybrid can be applied in other electrochemical sensing applications.