Aromatic Surfactant as Aggregating Agent for Aptamer-Gold Nanoparticle-Based Detection of Plasmodium Lactate Dehydrogenase

• Published in: Molecular biotechnology 2016-07, Vol.58 (7), p.497-508
• Main Authors: Jain, Priyamvada, Chakma, Babina, Singh, Naveen Kumar, Patra, Sanjukta, Goswami, Pranab
• Format: Article
• Language: English
• Subjects: Aptamers, Nucleotide - chemistry; Benzalkonium Compounds - chemistry; Biochemistry; Biological Techniques; Biosensing Techniques; Biotechnology; Cell Biology; Chemistry; Chemistry and Materials Science; Dehydrogenase; Enzymes; Gold - chemistry; Human Genetics; Humans; Isoenzymes - chemistry; Isoenzymes - genetics; Isoenzymes - isolation & purification; L-Lactate Dehydrogenase - chemistry; L-Lactate Dehydrogenase - genetics; L-Lactate Dehydrogenase - isolation & purification; Limit of Detection; Malaria; Malaria - diagnosis; Metal Nanoparticles - chemistry; Molecular Structure; Nanoparticles; Original Paper; Plasmodium falciparum; Plasmodium falciparum - enzymology; Plasmodium falciparum - genetics; Protein Science; Protozoan Proteins - chemistry; Protozoan Proteins - genetics; Protozoan Proteins - isolation & purification; SELEX Aptamer Technique; Surface-Active Agents - chemistry; Surfactants
• ISSN: 1073-6085; 1559-0305
• DOI: 10.1007/s12033-016-9946-x

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 δ G 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.