Controlling the Binding Efficiency of Surface Confined Antibodies through the Design of Mixed Self‐Assembled Monolayers

Abstract A plethora of different electronic and optoelectronic devices have been developed lately, for biosensing applications (e.g., label‐free, fast, and easier to operate) based on a detecting interface accommodating the biorecognition elements, anchored by thiolate self‐assembled monolayers (SAMs) on a gold surface. Here, a surface plasmon resonance (SPR) characterization of anti‐p24 anchored on different SAMs is performed to investigate the effect of the SAM structure on the antibodies’ packing efficiency and the sensors’ analytical figures of merit. Notably, the mixed SAM deposited from a solution 10:1 of 3‐mercaptopropionic acid and 11‐mercaptoundecanoic acid (11MUA) is compared to that resulting from a solution 10:1 of ad hoc synthesized N‐(2‐hydroxyethyl)‐3‐mercaptopropanamide (NMPA)/11MUA. Despite the improvement in the anti‐p24 surface coverage registered using the 11MUA/NMPA SAM, the latter produces a significant decrease in the antibodies’ binding efficiency against human immunodeficiency virus p24 protein. To provide a molecular rationale behind the SPR data, density functional theory calculations are also undertaken. A comprehensive physical view of the main competing phenomena affecting the biorecognition events at a biofunctionalized gold detecting interface is represented here

Design of a new tracking device for on-line beam range monitor in carbon therapy

Charged particle therapy is a technique for cancer treatment that exploits hadron beams, mostly protons and carbon ions. A critical issue is the monitoring of the beam range so to check the correct dose deposition to the tumor and surrounding tissues. The design of a new tracking device for beam range real-time monitoring in pencil beam carbon ion therapy is presented. The proposed device tracks secondary charged particles produced by beam interactions in the patient tissue and exploits the correlation of the charged particle emission profile with the spatial dose deposition and the Bragg peak position. The detector, currently under construction, uses the information provided by 12 layers of scintillating fibers followed by a plastic scintillator and a pixelated Lutetium Fine Silicate (LFS) crystal calorimeter. An algorithm to account and correct for emission profile distortion due to charged secondaries absorption inside the patient tissue is also proposed. Finally detector reconstruction efficiency for charged particle emission profile is evaluated using a Monte Carlo simulation considering a quasi-realistic case of a nonhomogenous phantom