| Autor: |
Ayres LB; Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States., Pimentel GJC; Brazilian Center for Research in Energy and Materials, Brazilian Nanotechnology National Laboratory, Campinas, São Paulo 13083-970, Brazil.; Institute of Chemistry, University of Campinas, Campinas, São Paulo 13083-970, Brazil., Costa JNY; Brazilian Center for Research in Energy and Materials, Brazilian Nanotechnology National Laboratory, Campinas, São Paulo 13083-970, Brazil.; Center for Natural and Human Sciences, Federal University of ABC, Santo André, São Paulo 09210-580, Brazil., Piazzetta MHO; Brazilian Center for Research in Energy and Materials, Brazilian Nanotechnology National Laboratory, Campinas, São Paulo 13083-970, Brazil., Gobbi AL; Brazilian Center for Research in Energy and Materials, Brazilian Nanotechnology National Laboratory, Campinas, São Paulo 13083-970, Brazil., Shimizu FM; Brazilian Center for Research in Energy and Materials, Brazilian Nanotechnology National Laboratory, Campinas, São Paulo 13083-970, Brazil., Garcia CD; Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States., Lima RS; Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States.; Brazilian Center for Research in Energy and Materials, Brazilian Nanotechnology National Laboratory, Campinas, São Paulo 13083-970, Brazil.; Institute of Chemistry, University of Campinas, Campinas, São Paulo 13083-970, Brazil.; Center for Natural and Human Sciences, Federal University of ABC, Santo André, São Paulo 09210-580, Brazil.; São Carlos Institute of Chemistry, University of São Paulo, São Carlos, São Paulo 13565-590, Brazil. |
| Abstrakt: |
High-throughput sensors are valuable tools for enabling massive, fast, and accurate diagnostics. To yield this type of electrochemical device in a simple and low-cost way, high-density arrays of vertical gold thin-film microelectrode-based sensors are demonstrated, leading to the rapid and serial interrogation of dozens of samples (10 μL droplets). Based on 16 working ultramicroelectrodes (UMEs) and 3 quasi-reference electrodes (QREs), a total of 48 sensors were engineered in a 3D crossbar arrangement that devised a low number of conductive lines. By exploiting this design, a compact chip (75 × 35 mm) can enable performing 16 sequential analyses without intersensor interferences by dropping one sample per UME finger. In practice, the electrical connection to the sensors was achieved by simply switching the contact among WE adjacent fingers. Importantly, a short analysis time was ensured by interrogating the UMEs with chronoamperometry or square wave voltammetry using a low-cost and hand-held one-channel potentiostat. As a proof of concept, the detection of Staphylococcus aureus in 15 samples was performed within 14 min (20 min incubation and 225 s reading). Additionally, the implementation of peptide-tethered immunosensors in these chips allowed the screening of COVID-19 from patient serum samples with 100% accuracy. Our experiments also revealed that dispensing additional droplets on the array (in certain patterns) results in the overestimation of the faradaic current signals, a phenomenon referred to as crosstalk. To address this interference, a set of analyses was conducted to design a corrective strategy that boosted the testing capacity by allowing using all on-chip sensors to address subsequent analyses (i.e., 48 samples simultaneously dispensed on the chip). This strategy only required grounding the unused rows of QRE and can be broadly adopted to develop high-throughput UME-based sensors. In practice, we could analyze 48 droplets (with [Fe(CN) 6 ] 4 - ) within ∼8 min using amperometry. |
