title: Aromatic Surfactant as Aggregating Agent for Aptamer-Gold Nanoparticle-Based Detection of Plasmodium Lactate Dehydrogenase.
abstract: A novel ssDNA aptamer (P38), with a 40 mer random region flanked by primer-binding sites on both sides, targeting Plasmodium falciparum lactate dehydrogenase (PfLDH) has been developed through systematic evolution of ligands by exponential enrichment (SELEX), including counter SELEX against human lactate dehydrogenase A and B (hLDH A and B). The 2D structure of P38 shows the presence of three stem loops with a δG of -9.18 kcal/mol. EMSA studies on P38 complexes with the increasing concentration of PfLDH revealed a dissociation constant of 0.35 µM. P38 has been exploited for the quantitative detection of PfLDH using cationic surfactant-mediated aggregation of gold nanoparticles (16-nm diameter) as an optical probe. Among the three different cationic surfactants, characterized by different hydrocarbon tail groups, benzalkonium chloride (BCK) was found to be most efficient with a limit of detection of 281 ± 11 pM. This BCK-based approach with the novel highly selective aptamer provides simple and sensitive detection of PfLDH in the clinically relevant range.
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
authors.forename: Priyamvada
authors.initials: P
authors.lastname: Jain
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
authors.forename: Babina
authors.initials: B
authors.lastname: Chakma
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
authors.forename: Naveen Kumar
authors.initials: NK
authors.lastname: Singh
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
authors.forename: Sanjukta
authors.initials: S
authors.lastname: Patra
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India. pgoswami@iitg.ernet.in.
authors.forename: Pranab
authors.initials: P
authors.lastname: Goswami
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001548:Benzalkonium Compounds / Q000737:chemistry*; D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D007770:L-Lactate Dehydrogenase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D000080864:Lactate Dehydrogenase 5; D057230:Limit of Detection; D008288:Malaria / Q000175:diagnosis; D053768:Metal Nanoparticles / Q000737:chemistry; D015394:Molecular Structure; D010963:Plasmodium falciparum / Q000201:enzymology* / Q000235:genetics; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D052156:SELEX Aptamer Technique; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D001548:Benzalkonium Compounds; D007527:Isoenzymes; D015800:Protozoan Proteins; D013501:Surface-Active Agents; D006046:Gold; D007770:L-Lactate Dehydrogenase; D000080864:Lactate Dehydrogenase 5; C409667:lactate dehydrogenase 1
keywords: Aggregation; Colorimetric assay; Gold nanoparticle; Malaria; Plasmodium