Kandaswamy Theyagarajan
@gachon.ac.kr
Post Doctoral Fellow
Gachon University
RESEARCH, TEACHING, or OTHER INTERESTS
Electrochemistry, Analytical Chemistry, Renewable Energy, Sustainability and the Environment, Materials Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
K Theyagarajan, Buddolla Anantha Lakshmi, and Young-Joon Kim
Elsevier BV
K Theyagarajan, Vadakke Purakkal Sruthi, Jitendra Satija, Sellappan Senthilkumar, and Young-Joon Kim
Elsevier BV
K Theyagarajan and Young-Joon Kim
MDPI AG
The modern healthcare system strives to provide patients with more comfortable and less invasive experiences, focusing on noninvasive and painless diagnostic and treatment methods. A key priority is the early diagnosis of life-threatening diseases, which can significantly improve patient outcomes by enabling treatment at earlier stages. While most patients must undergo diagnostic procedures before beginning treatment, many existing methods are invasive, time-consuming, and inconvenient. To address these challenges, electrochemical-based wearable and point-of-care (PoC) sensing devices have emerged, playing a crucial role in the noninvasive, continuous, periodic, and remote monitoring of key biomarkers. Due to their numerous advantages, several wearable and PoC devices have been developed. In this focused review, we explore the advancements in metal–organic frameworks (MOFs)-based wearable and PoC devices. MOFs are porous crystalline materials that are cost-effective, biocompatible, and can be synthesized sustainably on a large scale, making them promising candidates for sensor development. However, research on MOF-based wearable and PoC sensors remains limited, and no comprehensive review has yet to synthesize the existing knowledge in this area. This review aims to fill that gap by emphasizing the design of materials, fabrication methodologies, sensing mechanisms, device construction, and real-world applicability of these sensors. Additionally, we underscore the importance and potential of MOF-based wearable and PoC sensors for advancing healthcare technologies. In conclusion, this review sheds light on the current state of the art, the challenges faced, and the opportunities ahead in MOF-based wearable and PoC sensing technologies.
K Theyagarajan, Buddolla Anantha Lakshmi, Chaehyun Kim, and Young-Joon Kim
Elsevier BV
K Theyagarajan, Buddolla Anantha Lakshmi, and Young-Joon Kim
Elsevier BV
Michael Benjamin, Devaraj Manoj, K. Theyagarajan, Kathavarayan Thenmozhi, Duraisamy Saravanakumar, and Sellappan Senthilkumar
Elsevier BV
K. Theyagarajan and Young-Joon Kim
MDPI AG
Electrochemical biosensors are superior technologies that are used to detect or sense biologically and environmentally significant analytes in a laboratory environment, or even in the form of portable handheld or wearable electronics. Recently, imprinted and implantable biosensors are emerging as point-of-care devices, which monitor the target analytes in a continuous environment and alert the intended users to anomalies. The stability and performance of the developed biosensor depend on the nature and properties of the electrode material or the platform on which the biosensor is constructed. Therefore, the biosensor platform plays an integral role in the effectiveness of the developed biosensor. Enormous effort has been dedicated to the rational design of the electrode material and to fabrication strategies for improving the performance of developed biosensors. Every year, in the search for multifarious electrode materials, thousands of new biosensor platforms are reported. Moreover, in order to construct an effectual biosensor, the researcher should familiarize themself with the sensible strategies behind electrode fabrication. Thus, we intend to shed light on various strategies and methodologies utilized in the design and fabrication of electrochemical biosensors that facilitate sensitive and selective detection of significant analytes. Furthermore, this review highlights the advantages of various electrode materials and the correlation between immobilized biomolecules and modified surfaces.
K. Theyagarajan, Vadakke Purakkal Sruthi, Devarasu Mohanapriya, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
Elsevier
Prathapaneni Manusha, K. Theyagarajan, Mari Elancheziyan, Harisingh Shankar, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
The Electrochemical Society
A simple and selective enzyme-free electrochemical sensor for H2O2 has been designed and fabricated using ionic liquid (IL) tagged anthraquinone (AQ) modified electrode (AQ-PF6-IL). This newly synthesized AQ-PF6-IL has been systematically characterized, after which it has been immobilized over a screen-printed electrode to produce AQ-PF6-IL/SPE. The electrochemical investigation of AQ-PF6-IL/SPE displayed a set of distinct redox peaks attributable to the anthraquinone/anthrahydroquinone redox pair. Interestingly, AQ-PF6-IL/SPE has shown enhanced peak current at reduced formal potential for AQ, when compared to AQ/SPE. Further, the electrocatalytic activity of AQ-PF6-IL/SPE towards the reduction of H2O2 was investigated with the sequential addition of H2O2. A rapid and appreciable enhancement in cathodic peak currents was observed and thus demonstrating the excellent electrochemical reduction of H2O2 at the newly developed sensor. Besides, AQ-PF6-IL/SPE established a good linear behaviour over a concentration range of 10–1228 μM with a high sensitivity of 0.281 μA μM−1 cm−2 and low detection limit of 2.87 μM. The fabricated sensor displayed excellent stability, good anti-interference ability, along with acceptable reproducibility. The superior properties of the developed sensor could be attributed to the newly designed AQ-PF6-IL, wherein the redox characteristics of AQ mediator are integrated with the high stability and conductivity of IL.
Mari Elancheziyan, Sivarasan Ganesan, K. Theyagarajan, Murugesan Duraisamy, Kathavarayan Thenmozhi, Chih-Huang Weng, Yao-Tung Lin, and Vinoth Kumar Ponnusamy
Elsevier BV
Mari Elancheziyan, K. Theyagarajan, Vinoth Kumar Ponnusamy, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
Elsevier BV
Manoharan Murphy, K. Theyagarajan, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
Elsevier BV
K. Theyagarajan, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
Elsevier
K. Theyagarajan, Prakash Sinha Aayushi, Anitha Devadoss, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
Royal Society of Chemistry
K. Theyagarajan, Mari Elancheziyan, Prakash Sinha Aayushi, and Kathavarayan Thenmozhi
Elsevier BV
Kandaswamy Theyagarajan, Sangeeta Yadav, Jitendra Satija, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
American Chemical Society (ACS)
Creation of interfaces with a prudent design for the immobilization of biomolecules is substantial in the construction of biosensors for real-time monitoring. Herein, an adept biosensing interface was developed using a nanoconjugated matrix and has been employed toward the electrochemical determination of hydrogen peroxide (H2O2). The anionic gold nanoparticle (AuNP) was electrostatically tethered to cationic redox ionic liquid (IL), to which the horseradish peroxidase (HRP) enzyme was covalently immobilized to form a nanobioconjugate. The anthracene-substituted, aldehyde-functionalized redox IL (CHO-AIL) was judiciously designed with the (i) imidazolium cation for electrostatic interaction with AuNPs, (ii) anthracene moiety to mediate the electron transfer, and (iii) free aldehydic group for covalent bonding with a free amine group of the enzyme. Thus, the water-soluble HRP is effectively bonded to the CHO-AIL on a glassy carbon electrode (GCE) via imine bond formation, which resulted in the formation of the HRP-CHO-AIL/GCE. Electrochemical investigations on the HRP-CHO-AIL/GCE reveal highly stable and distinct redox peaks for the anthracene/anthracenium couple at a formal potential (E°') of -0.47 V. Electrostatic tethering of anionic AuNPs to the HRP-CHO-AIL promotes the electron transfer process in the HRP-CHO-AIL/AuNPs/GCE, as observed by the reduction in the formal potential to -0.42 V along with the enhancement in peak currents. The HRP-CHO-AIL/AuNPs/GCE has been explored toward the electrocatalytic detection of H2O2, and the modified electrode demonstrated a linear response toward H2O2 in the concentration range of 0.02-2.77 mM with a detection limit of 3.7 μM. The developed biosensor ascertained predominant selectivity and sensitivity in addition to remarkable stability and reproducibility, corroborating the suitableness of the platform for the effectual biosensing of H2O2. The eminent performance realized with our biosensor setup is ascribed to the multifunctional efficacy of this newly designed nanobioconjugate.
Manoharan Murphy, K. Theyagarajan, Kathavarayan Thenmozhi, and Sellappan Senthilkumar
Wiley
A. Pangajam, K. Theyagarajan, and K. Dinakaran
Elsevier BV
M. Elancheziyan, K. Theyagarajan, D. Saravanakumar, K. Thenmozhi, and S. Senthilkumar
Elsevier BV
K. Theyagarajan, Duraisamy Saravanakumar, Sellappan Senthilkumar, and Kathavarayan Thenmozhi
Springer Science and Business Media LLC
Herein, we have designed and demonstrated a facile and effective platform for the covalent anchoring of a tetrameric hemoprotein, hemoglobin (Hb). The platform comprises of naphthyl substituted amine functionalized gel type hydrophobic ionic liquid (NpNH2-IL) through which the heme protein was covalently attached over a glassy carbon electrode (Hb-NpNH2-IL/GCE). UV-vis and FT-IR spectral results confirmed that the Hb on NpNH2-IL retains its native structure, even after being covalently immobilized on NpNH2-IL platform. The direct electron transfer of redox protein could be realized at Hb-NpNH2-IL/GCE modified electrode and a well resolved redox peak with a formal potential of −0.30 V and peak separation of 65 mV was observed. This is due to the covalent attachment of highly conducting NpNH2-IL to the Hb, which facilitates rapid shuttling of electrons between the redox site of protein and the electrode. Further, the fabricated biosensor favoured the electrochemical reduction of bromate in neutral pH with linearity ranging from 12 to 228 µM and 0.228 to 4.42 mM with a detection limit and sensitivities of 3 µM, 430.7 µA mM−1 cm−2 and 148.4 µA mM−1 cm−2 respectively. Notably, the fabricated biosensor showed good operational stability under static and dynamic conditions with high selectivity and reproducibility.
Manoharan Murphy, K. Theyagarajan, Prabusankar Ganesan, Sellappan Senthilkumar, and Kathavarayan Thenmozhi
Elsevier BV
Devaraj Manoj, K. Theyagarajan, Duraisamy Saravanakumar, Sellappan Senthilkumar, and Kathavarayan Thenmozhi
Elsevier BV