PEGylated Gold Nanoparticles as Novel Agglutination Enhancement Medium for Antibody Screening Test

To develop a novel enhancement medium using polyethylene glycol (PEG)‐conjugated gold nanoparticles (AuNPs) for improved detection of clinically significant alloantibodies in antibody screening tests (AST), addressing the limitations of low ionic strength solution (LISS). PEG AuNPs were synthesized through a one‐step method and characterized using UV–Visible spectroscopy, EFTEM, FESEM, particle size analysis, zeta potential measurement, and FT‐IR spectroscopy. The PEG AuNPs' performance was evaluated against LISS in 120 plasma samples (both antibody‐positive and negative) by scoring RBC agglutination reactions. Synthesized PEG AuNPs showed a ruby red color with a single absorption peak at 529 nm, confirming AuNP surface plasmon resonance. Spherical colloids averaged 152.73 ± 19.59 nm, with stability indicated by a zeta potential of −6.24 ± 0.57 mV. Significantly higher RBC agglutination scores were observed with PEG AuNPs during the anti‐human globulin (AHG) phase ( p = 0.010), especially for anti‐D and anti‐Le a /anti‐Le b antibodies ( p = 0.007 and 0.036, respectively). PEGylated AuNPs significantly enhanced RBC agglutination reactions compared to LISS, particularly for anti‐D and combined anti‐Le a /anti‐Le b antibodies, presenting a promising alternative for AST.