Exonuclease III-Driven Dual-Amplified Electrochemical Aptasensor Based on PDDA-Gr/PtPd@Ni-Co Hollow Nanoboxes for Chloramphenicol Detection

Abstract

Herein, a hierarchically porous Zr-MOF-labeled electrochemical aptasensor based on the composite of PtPd@Ni-Co hollow nanoboxes (PtPd@Ni-Co HNBs) and poly (diallyldimethylammonium chloride)-functionalized graphene (PDDA-Gr) was developed for ultrasensitive detection of chloramphenicol (CAP). PtPd@Ni-Co HNBs have excellent conductivity and provide binding sites for aptamers; the functionalized PDDA-Gr improves its dispersibility and conductivity as a substrate material, which can be successfully used to increase the electrode surface area and support more PtPd@Ni-CoHNBs. Besides, hierarchically porous Zr-MOFs (HP-UiO-66) were utilized as signal probes and showed a stronger load capacity for signal molecules than conventional UiO-66. In the presence of CAP, two ingeniously designed Exo III-assisted cyclic amplification strategies further improved the sensitivity of the aptasensor: CAP causes cycle I to release a large amount of trigger DNA (Tr DNA), and then, Tr DNA initiated cycle II, which causes the exposed capture DNA to further bind the signal probes. With these advantages, the constructed aptasensors performed with satisfactory sensitivity in a wide linear range (10 fM–10 nM) and a detection limit of 0.985 fM. Several signal amplification strategies adopted in this study have effectively improved the performance of the sensor, providing a new avenue for the development of ultrasensitive sensors in the food analysis field.

Advances and effectiveness of metal–organic framework based bio/chemical sensors for rapid and ultrasensitive probing of antibiotic residues in foods

“…In the presence of CMP, the EXO I release a huge amount of trigger DNA (Tr DNA), and this Tr DNA initiates cycle II, which results in the binding of the exposed capture DNA to the signal probes to increase the current flow. This aptasensorwide linear range (10 fM−10 nM) and a detection limit of 0.32pgL -1 [111] . A simple, rapid, selective, sensitive, and low-cost aptasensor for the detection of tetracycline using a Fe MOF(NH 2 -MIL-101(Fe)/CNF@AuNPs) synthesized using the combination of 4 different methods such as hydrothermal, electrospinning, pyrolysis, and electrodeposition resulting in increased sensitivity to the analyte.…”

“…This aptasensor has a wide linear range (10 fM to 10 nM) and a detection limit of 0.32 pg L −1 . 111…”

“…This aptasensor has a wide linear range (10 fM to 10 nM) and a detection limit of 0.32 pg L −1 . 111 A simple, rapid, selective, sensitive, and low-cost aptasensor for the detection of tetracycline using an Fe MOF(NH 2 -MIL-101(Fe)/CNF@AuNPs) was synthesized using the combination of 4 different methods such as hydrothermal, electrospinning, pyrolysis, and electrodeposition resulting in increased sensitivity to the analyte. In the presence of TC, the aptamer-analyte complex on the surface of the electrode reduces the electron transfer on the surface of the electrode due to impedance resulting in reduced current.…”

Electrochemical Aptasensors for Antibiotics Detection: Recent Achievements and Applications for Monitoring Food Safety

“…Although most of the details concerning the design and performance of electrochemical aptasensors are presented in Table 2 , it seems important to highlight the most urgent trends in their development and application. Among modifiers intended for aptamer immobilization and signal generation, MOF-/COF-based architectures are intensively studied [ 176 , 180 , 188 , 189 , 218 , 221 , 235 , 265 , 266 , 270 ]. They are rather easily synthesized by hydrothermal methods and can either accumulate reactants including aptamers or serve as carriers for labels.…”

Incorporating Fullerenes in Nanoscale Metal–Organic Matrixes: An Ultrasensitive Platform for Impedimetric Aptasensing of Tobramycin

“…Electrochemical biosensors based on aptamers are the most extensive and useful detection method due to the sensitive and quick response of electrochemical signals and the highly specific recognition of aptamers. − Recently, many advanced materials have been developed for enhanced electrochemical detection performance, such as carbon quantum dots, , metal nanoparticles, , porous organic polymers, , and carbon nanomaterials. , Especially, Zr-based MOFs have been utilized as functional materials to prepare electrochemical aptasensors due to the superior affinity between Zr­(IV) chelating sites and phosphate groups of aptamers. − Meanwhile, nanoscale particles can explore more functional sites in the outer surface to increase the interaction between MOFs and aptamers for fabricating highly sensitive aptasensors. On the other hand, several C 60 nanohybrid-based electrochemical aptasensors have been reported to detect analytes on account of their excellent stability and electrochemical activity. − Although no electrochemical aptasensor based on C 60 @Zr-MOF hybrid materials has been reported, previous studies indicate that such hybrid materials have great applicability in electrochemical aptasensing applications.…”