Browsing by Author "Akriti Srivastava"

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A dual epitope-imprinted polymer@AuNP-MoS2 nanosheets-EQCM sensor for antibody free detection of SipD protein of Salmonella typhi bacteria with high selectivity
(Elsevier B.V., 2025) Akriti Srivastava; Ashish Kumar Kushwaha; Pinky Sagar; Anirban Parida; Roop Shikha Singh; Sanjay Kumar Srivastava; Richa Raghuwanshi; Gopal Nath; Meenakshi K. Singh
Dual-epitope imprinted EQCM sensor for selective and sensitive detection of Salmonella typhi bacterial protein is fabricated on gold nanoparticle decorated MoS2 nanosheets (AuNPs-MoS2NSs). Salmonella invasive protein D (SipD) binds to the needle protein and appears capable of interacting with the translocon complex to infect the host. Potential B cell antigenic epitope sequences from bacterial tip protein, SipD were intentionally tagged with cysteine and are used as dual templates to fabricate MIP sensor using methacryloyloxyethyl phosphorylcholine (MPC), benzyl methacrylate (BMA) and methacrylic acid (MAA) as monomers and N , N ′-methylene- bis -acrylamide as a crosslinker. The monomers chosen through docking produced a DEIP-EQCM sensor. The sensor was able to show specific binding towards the blood samples of infected patients, even in the presence of ‘matrix’ of ‘real’ samples and other plasma proteins. It has shown excellent specificity, sensitivity and selectivity in sensing range of 100–1000 nM with detection limit 1.65 nM (Epitope I) and 0.025 nM (Epitope II) and limit of quantification as 5.03 nM (Epitope I) and 0.075 nM (Epitope II) for the two epitope sequences imprinted. Sip D protein binding was substantiated by SDS-PAGE analysis. The repetitive experimental runs could not mutilate the specific geometries of respective imprinted cavities and the DEIP-EQCM sensor can be proposed for antibody free detection of Sip D protein. © 2025 The Authors.
A polypyrrole-coated GCE sensor for sensitive detection of 5-fluorouracil via molecular imprinting
(Royal Society of Chemistry, 2025) Manjeet Harijan; Akriti Srivastava; Meenakshi K. Singh
Cytotoxic drug 5-fluorouracil (5-FU) is a fluorine derivative of uracil; it is one of the most significant medications used to treat cancers of the stomach, breast, colon, pancreas, and cervical regions. Here, a reliable, rapid, highly sensitive and selective method is proposed for determining 5-FU in real samples. In this study, a molecularly imprinted polymer (MIP) based electrochemical sensor is designed for the sensitive and selective determination of 5-FU. The MIP was developed by the electropolymerization of a pyrrole thin film around template molecules (5-FU) on a glassy carbon electrode (GCE). The sensor was characterized after each stage of fabrication using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The MIP sensor exhibited a wide linear range for determining 5-FU from 2-42 μM. The developed sensor achieved a limit of detection (LOD) and limit of quantification (LOQ) of 0.605 μM and 1.834 μM, respectively. The applicability of the proposed sensor was examined for 5-FU determination in real samples. The MIP sensor exhibited excellent selectivity, repeatability, stability, and commercialization potential for 5-FU detection. Furthermore, the proposed method offers significant advantages over existing electrochemical techniques for 5-FU detection. This method provides single-step preparation alongside simple template molecule removal by cyclic voltammetry scans and does not need any extracting solvents. © 2025 The Royal Society of Chemistry.
Computational designing and synthesis of epitope imprinted sensor with zwitterionic polymeric matrix for sensitive, specific and selective sensing of protein
(Elsevier Inc., 2025) Akriti Srivastava; Richa Raghuwanshi; Meenakshi K. Singh
Lactoferrin (Lf) protein is a member of the transferrin family, present in mature milk, transitional milk, and colostrum milk. It has antibacterial, antiviral, immunomodulatory, anticancer, and prebiotic properties, and vital in many biomedical and biotechnological applications, and also serve as biomarker for several disorders, viz. Alzheimer's disease, inflammatory bowel disease, subclinical mastitis, dry eye disease, etc. Here, N-terminal region peptide of Lf is chosen for epitope imprinting. This epitope sequence was imprinted on electrochemical quartz crystal microbalance (EQCM) electrode using multiple monomer approach. The monomers were chosen through in silico molecular docking for to select appropriate set of monomers for chosen peptide sequence as target analyte. A zwitterionic monomer 2-methacryloyloxyethyl phosphorylcholine (MPC) with benzyl methacrylate (BMA) and 4-aminothiophenol (4-ATP) were predicted for crafting imprinted polymer matrix. On extraction of the peptide (epitope) sequences, imprinted cavities were capable to selectively and specifically capture intended peptide (epitope) sequences in laboratory samples as well as ‘real’ samples. Selectivity of sensor was examined through mismatched peptide sequences and certain plasma proteins also. The sensor was able to show specific binding towards the ‘real’ samples of milk, even in the presence of ‘matrix’ and other proteins. The limit of detection and quantification was found to be 5.25 nM and 17.51 nM respectively with imprinting factor as 10.91. Good analytical performance was shown by the devised technique, high sensitivity and selectivity with no matrix interference. © 2025 Elsevier B.V.
Dual template (epitope) imprinted electrode for sensing bacterial protein with high selectivity
(John Wiley and Sons Ltd, 2024) Akriti Srivastava; Manjeet Harijan; Rajniti Prasad; Meenakshi Singh
Epitope imprinting has shown better prospects to synthesize synthetic receptors for proteins. Here, dual epitope imprinted polymer electrode (DEIP) matrix was fabricated on gold surface of electrochemical quartz crystal microbalance (EQCM) for recognition of target epitope sequence in blood samples of patients suffering from brain fever. Epitope sequences from outer membrane protein Por B of Neisseria meningitidis (MC58) bacteria predicted through immunoinformatic tools were chosen for imprinting. Self-assembled monolayers (SAM) of cysteine appended epitope sequences on gold nanoparticles were subjected to polymerization prior to electrodeposition on gold coated EQCM electrode. The polymeric matrix was woven around the cysteine appended epitope SAMs through multiple monomers (3-sulfo propyl methacrylate potassium salt (3-SPMAP), benzyl methacrylate (BMA)) and crosslinker (N, N′-methylene-bis-acrylamide). On extraction of the peptide sequences, imprinted cavities were able to selectively and specifically bind targeted epitope sequences in laboratory samples as well as ‘real’ samples of patients. Selectivity of sensor was examined through mismatched peptide sequences and certain plasma proteins also. The sensor was able to show specific binding towards the blood samples of infected patients, even in the presence of ‘matrix’ and other plasma proteins such as albumin and globulin. Even other peptide sequences, similar to epitope sequences only with one or two amino acid mismatches were also unable to show any binding. The analytical performance of DEIP-EQCM sensor was tested through selectivity, specificity, matrix effect, detection limit (0.68–1.01 nM), quantification limit (2.05–3.05 nM) and reproducibility (RSD ~ 5%). Hence, a diagnostic tool for bacterium causing meningitis is successfully fabricated in a facile manner which will broaden the clinical access and make efficient population screening feasible. © 2024 John Wiley & Sons Ltd.
Patents based on molecularly imprinted polymers: Exploring their commercial potential
(Elsevier, 2023) Parul Chugh; Lashika Batra; Akriti Srivastava; Rachana Singh
Science and technology are working toward developing materials that can imitate molecular recognition–based activities present in life. Molecular imprinting is a technique that solves this problem by imparting polymeric materials with antibody-like recognition properties. Many of the practical issues traditionally associated with molecularly imprinted polymers (MIPs), such as difficulties in imprinting proteins, poor compatibility with aqueous environments, template leakage, and the presence of heterogeneous populations of binding sites in the polymers that contribute to high levels of nonspecific reactivity, have recently seen significant progress. This development is linked to a technologically driven transition in MIP research from bulk polymer to nanomaterial forms. The purpose of this chapter is to shed light on recent advancements in this sector and to provide a critical analysis of the current state of patents in the field as well as its commercialization possibilities. © 2023 Elsevier Inc. All rights reserved.
Unravelling the Potential of Zwitterionic Polymers in Molecular Imprinting
(American Chemical Society, 2025) Meenakshi K. Singh; Akriti Srivastava; Moumita Mandal
Molecularly imprinted polymers (MIPs) are a class of molecular receptors that are the closest imitation of biological receptors. They are often called “artificial enzymes”. The capability of the MIPs to bind bioactive molecules under specific conditions creates molecular imprinting technology as having considerable potential for customized applications. Polymerization in the presence of a “template” molecule with the assistance of monomers, cross-linkers, and initiators leads to MIPs on extraction of the template molecule from the polymeric matrices. Conventionally neutral monomers were utilized for molecular imprinting. Recently, zwitterionic polymers, having innumerable advantages over nonionic polymers, were realized to be an advantageous choice as a polymeric matrix for imprinting. This review article presents an overview of sulfobetaine, carbobetaine, and phosphobetaine polymers as imprinting matrices for a range of template(s). Zwitterionic polymers are accomplished with biocompatibility, low cytotoxicity, negligible immunogenicity, systematic stability, and long circulation time, and can alleviate quick recognition by the immune system and delayed blood clearance from the body. They can be a fitting candidate for imprinting, especially of biomolecules. The molecular imprinting work on zwitterionic polymers is presented here, which will encourage researchers working in this area. © 2025 American Chemical Society.