Fig 1: Nanoplasmonic inhibition assay for D3R-antagonist antipsychotic drug. (A) Sensorgrams obtained for indirect detection of buspirone at different concentrations (5 nM–5 mM). (B) Standard dose-response inhibition curve for indirect detection of Buspirone. Plots represent mean and standard deviation of each buspirone concentration (1 nM–5 mM) measured in triplicate. (C) Sensorgrams obtained for negative control drugs (i.e., etoposide and APAP), compared to pure D3R-AuNPs detection. (D) Signal comparison between dopamine, antipsychotic drugs, and control drugs at the same concentration (6.5 µM). Statistical analysis (n = 5) confirmed that differences between control drugs signals and free D3R are not significant (p < 0.05).
Fig 2: Conceptual illustration of the label-free biosensors working principle and drug screening assay design. (A) Schematics of the electrochemical sensor based on carbon screen-printed electrodes (EPS). (B) Randles equivalent circuit for an electrode in electrolyte contact. (C) Illustrative representation of electrochemical impedance spectroscopy (EIS) signals, before and after interaction of the DA-BSA conjugate with D3R for the case of APD or control drug interactions. (D) Schematics of the nanoplasmonic sensor based on nanohole arrays. (E) Illustrative representation of extraordinary optical transmission (EOT) spectroscopy signal, before and after analyte capture. (F) Illustrative representation of the real-time sensorgram extracted from spectroscopic displacements during the analyte capture. (G) Schematics of the APD screening assay based on indirect competitive detection: (i) Standard: dopamine binds to D3R in solution and impedes its binding to the DA-BSA conjugate; (ii) A good antipsychotic drug (APD) will also bind to D3R and hamper its binding to the DA-BSA conjugate; and (iii) a non-specific drug will not bind to D3R and it will bind to the DA-BSA conjugate.
Fig 3: Characterization of the nanoplasmonic biosensor for indirect DA detection. (A) Sensorgrams obtained for the detection of pure D3R and gold nanoparticles conjugated D3R (D3R-AuNPs) on the DA-BSA functionalized surface. (B) Sensorgrams obtained for indirect detection of dopamine at different concentrations (5 nM–5 mM). (C) Standard dose-response inhibition curve for indirect detection of DA. Plots represent mean and standard deviation of each DA concentration (1 nM–5 mM) measured in triplicate.
Fig 4: Characterization of EC biosensor for indirect DA detection. (A) Nyquist plots drawn for different stages of functionalization of CSPE; bare, BSA-DA conjugate-immobilized and D3R (dilution: 1/1000). (B) Indirect detection of DA at various concentration; 0, 10, 20, 50, 100 nM. Color code: D3R: bordeaux; bare: black; BSA-DA conjugate: purple. (C) Calibration curve of EC biosensor for indirect DA detection based on normalized Rct values. Each value represents the mean and SD of five measurements.
Supplier Page from Abcam for Dopamine Receptor D3/DRD3 peptide