Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add more filters










Database
Language
Publication year range
1.
ACS Pharmacol Transl Sci ; 6(1): 92-99, 2023 Jan 13.
Article in English | MEDLINE | ID: mdl-36654753

ABSTRACT

A cost-effective, deployable, and quantitative progesterone biosensor is desirable for regular progesterone sensing in biological and environmental samples to safeguard public health. Aptasensors have been shown to be affordable as compared to antibody-based sensors, but so far, none of the progesterone aptamers could detect it in undiluted and unprocessed biological samples. Thus, to select an aptamer suitable for biosensing in unprocessed biological samples, a modified magnetic bead-based approach with counter-selection in milk and serum was performed. G-quadruplex forming progesterone aptamers were preferentially screened through in silico, gold nanoparticle-based adsorption-desorption assay and circular dichroism spectroscopy. GQ5 aptamer showed extended stability and a high progesterone binding affinity (K D 5.29 ± 2.9 nM) as compared to any other reported progesterone aptamers (P4G11 and P4G13). Under optimized conditions, GQ5 aptamer was coated on the gold electrode to develop an impedimetric aptasensor (limit of detection: 0.53, 0.91, and 1.9 ng/mL in spiked buffer, undiluted milk, and serum, respectively, with the dynamic range of detection from 0.1 to 50 ng/mL in buffer and 0.1 to 30 ng/mL in both milk and serum). The aptasensor exhibited a very high level of κ value (>0.9) with ELISA to detect progesterone in milk and serum. The aptasensor could be regenerated three times and can be stored for up to 10 days at 4 °C. Therefore, GQ5 may be used to develop a portable impedimetric aptasensor for clinical and on-site progesterone sensing in various biological and environmental samples.

2.
PLoS Negl Trop Dis ; 15(10): e0009841, 2021 10.
Article in English | MEDLINE | ID: mdl-34634067

ABSTRACT

Development of a rapid, on-site detection tool for snakebite is highly sought after, owing to its clinically and forensically relevant medicolegal significance. Polyvalent antivenom therapy in the management of such envenomation cases is finite due to its poor venom neutralization capabilities as well as diagnostic ramifications manifested as untoward immunological reactions. For precise molecular diagnosis of elapid venoms of the big four snakes, we have developed a lateral flow kit using a monoclonal antibody (AB1; IgG1 - κ chain; Kd: 31 nM) generated against recombinant cytotoxin-7 (rCTX-7; 7.7 kDa) protein of the elapid venom. The monoclonal antibody specifically detected the venoms of Naja naja (p < 0.0001) and Bungarus caeruleus (p<0.0001), without showing any immunoreactivity against the viperidae snakes in big four venomous snakes. The kit developed attained the limit of quantitation of 170 pg/µL and 2.1 ng/µL in spiked buffer samples and 28.7 ng/µL and 110 ng/µL in spiked serum samples for detection of N. naja and B. caeruleus venoms, respectively. This kit holds enormous potential in identification of elapid venom of the big four snakes for effective prognosis of an envenomation; as per the existing medical guidelines.


Subject(s)
Colorimetry/methods , Cytotoxins/analysis , Elapidae/immunology , Immunoassay/methods , Immunotoxins/analysis , Snake Venoms/analysis , Animals , Antibodies, Monoclonal/analysis , Antibodies, Monoclonal/immunology , Bungarus/genetics , Bungarus/physiology , Cytotoxins/genetics , Cytotoxins/immunology , Elapid Venoms/analysis , Elapid Venoms/genetics , Elapid Venoms/immunology , Elapidae/physiology , Immunotoxins/genetics , Immunotoxins/immunology , Naja naja/immunology , Naja naja/physiology , Snake Venoms/immunology , Viperidae/immunology , Viperidae/physiology
3.
Food Chem ; 356: 129659, 2021 Sep 15.
Article in English | MEDLINE | ID: mdl-33812186

ABSTRACT

Oxytetracycline (OTC), one of the largely used antibiotic in veterinary practice has been banned due to its potential side effects. Development of a field applicable and affordable kit to detect OTC will help to eliminate such milk from human consumption. An aptamer has been designed (27 nt; Kd = 29.2 ± 19.4 nM) through rational truncation. OTC interacts with this aptamer in G rich regions as confirmed by molecular modelling and circular dichroism spectroscopy. To develop a lateral flow based aptasensor, OTC was conjugated with a 7 kDa carrier protein to immobilize onto the nitrocellulose membrane. Using 0.125 µM aptamer-gold conjugate, assay could visually detects upto 5 ng/mL of OTC in spiked milk within 10 mins [Limit of quantitation (LOQ)-0.254 ± 1.62 ng/mL; permissible limit 100 ng/mL]. It showed no cross reactivity with components of milk and data correlated with analysis done through HPLC.


Subject(s)
Anti-Bacterial Agents/analysis , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Milk/chemistry , Oxytetracycline/analysis , Animals , Carrier Proteins/chemistry , Gold/chemistry , Limit of Detection , Metal Nanoparticles/chemistry , Milk/metabolism , Point-of-Care Systems
SELECTION OF CITATIONS
SEARCH DETAIL
...