Highly sensitive colorimetric aptasensor for 17β‐estradiol detection in milk based on the repetitive‐loop aptamer

Abstract

Trace of 17β‐estradiol (E2) contamination in food has been a concern for its negative impacts on human health, leading to the need for an E2‐monitoring system. This work reported a new simple, sensitive, and colorimetric E2 detection based on the designed repetitive‐loop aptamer and gold nanoparticles (AuNPs). The designed aptamers (L2–L5) exhibited a higher binding capability to E2 than the original truncated aptamer (L1). Although L3–L5 aptamers exhibited the highest binding capability, only L3‐aptasensor demonstrated the sensitive detection of E2 in a range of 0.05−0.8 nM, with the limit of detection at 13.1 pM. The developed L3‐aptasensor was 7.7‐folds more sensitive for E2 detection than the L1‐aptasensor. It selectively detected E2, but not the other tested chemicals with similar structures: progesterone, genistein, diethylstilbestrol, bisphenol A, and chloramphenicol. The L3‐aptasensor efficiently detected E2 spiked in milk samples within the precision acceptance criterion of recovery rates (100.1%−113.0%) and the relative standard deviations (5.24%−11.06%). These results demonstrated the development of a new aptasensor based on the designed repetitive‐loop aptamer that could enhance E2‐detection sensitivity and be potentially used for detecting E2 in milk samples with high accuracy and reliability.

A new colorimetric aptasensor for paraquat detection based on the designed aptamer with multiple paraquat binding sites in combination with gold nanoparticles

“…The long-length aptamer exhibits a strong absorption on the surface of AuNPs, resulting in more stable dispersion of AuNPs and lower capability of the aptasensor to detect paraquat at low concentration. 30 Based on the C LOD values, the R3- and R4-aptasensors are 2.14 and 1.59 times more sensitive than the R1-aptasensor ( C LOD = 2.76 nM), respectively (Fig. 7(D)).…”

“…The optimized pH was dened as the pH value that yielded the maximum absorbance ratio between A 650 and A 525 . Additionally, the optimization of temperature was determined by incubating AuNPs (7 nM) and aptamer (25 nM) at different temperatures (20,25,30,35, and 40 °C) for 30 min. Then, paraquat (50 nM) was added and incubated for an additional 30 min.…”

17β-estradiol biosensors based on different bioreceptors and their applications

“…This operation effectively increased the compatibility between the aptamer and E2 as well as the performance of the sensor. In Pakawat Kongpreecha team’s work ( Kongpreecha et al, 2023 ), the E2 aptamer was required to wrap gold nanoparticles. Therefore, the original E2 aptamer (original E2 aptamer 22-mer (5′-GCC​GTT​TGG​GCC​CAA​GTT​CGG​C-3′)) structure was removed, and two to five loops were repeatedly added to determine which structure was most effective for E2 recognition.…”

“…(B) Remove and repeat the E2 aptamer structure. Reprinted with permission from Kongpreecha et al (2023) . (C) Split E2 aptamer.…”

A self-powered electrochemical aptasensor for the detection of 17β-estradiol based on carbon nanocages/gold nanoparticles and DNA bioconjugate mediated biofuel cells

“…27,28 Accordingly, developing efficient and sensitive methods for the monitoring of E2 levels is of great significance. So far, many different techniques have been established for the determination of E2, such as gas chromatography/ liquid chromatography-mass spectrometry (GC/LC-MS), 29,30 enzyme-linked immunosorbent assay (ELISA), 31,32 colorimetry, [33][34][35] fluorescence, [36][37][38][39] electrochemistry, [40][41][42][43][44][45][46] and surface-enhanced Raman spectroscopy. 47,48 Nevertheless, these methods might suffer from the high cost of devices, the need for high levels of technical skill, low sensitivity, cumbersome operation processes and the need for sample pretreatment.…”