Stimuli-responsive SERS biosensor for ultrasensitive tetracycline sensing using EDTA-driven PEI@CaCO 3 microcapsule and CS@FeMMs

• Published in: Biosensors & bioelectronics 2023-04, Vol.226, p.115122
• Main Authors: Li, Huanhuan, Geng, Wenhui, Qi, Zhixiong, Ahmad, Waqas, Haruna, Suleiman A, Chen, Quansheng
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate; Anti-Bacterial Agents; Aptamers, Nucleotide; Biosensing Techniques - methods; Capsules; Chitosan; Edetic Acid; Gold; Limit of Detection; Metal Nanoparticles; Microspheres; Spectrum Analysis, Raman - methods; Tetracycline
• ISSN: 1873-4235
• DOI: 10.1016/j.bios.2023.115122

In this work, a stimuli-responsive SERS biosensor was fabricated for tetracycline (TTC) by "signal-on" strategy using (EDTA)-driven polyethyleneimine grafted calcium carbonate (PEI@CaCO ) microcapsule and chitosan-Fe magnetic microbeads (CS@FeMMs). Initially, aptamer conjugated magnetic-bead CS@FeMMs@Apt with superparamagnetism and excellent biocompatibility was employed as capture probe, which facilitated the rapid and easy magnetic separation. Subsequently, the PEI cross-linked layer and aptamer network layer were constructed onto the outer layer of CaCO @4-ATP microcapsule to form sensing probes (PEI@CaCO @4-ATP@Apt) via the layer-by-layer assembly method. In the presence of TTC, a sandwich SERS-assay was exploited by aptamer recognition induced target-bridged strategy. When the solution of EDTA was added, the core layer of CaCO would be dissolved quickly, destroying the microcapsule to release 4-ATP. The released 4-ATP could be quantitatively monitored by dripping the supernatant onto the AuNTs@PDMS SERS platform, resulting in a strong Raman "signal-on". Under the optimal conditions, a good linear relationship was established with a correlation coefficient (R ) of 0.9938 and a LOD of 0.03 ng/mL. Additionally, the application capacity of the biosensor to detect TTC was also affirmed in food matrixes, and the results were consistent with the standard ELISA method (P > 0.05). Hence, this SERS biosensor affords extensive application prospects for TTC detection with multiple merits such as high sensitivity, environment friendliness, and high stability.