A Three-Channel Reflected SH-SAW Biosensor for Cardiovascular Risk Evaluation

Cardiovascular disease (CVD) remains a global health challenge, with biomarkers such as apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB) playing a critical role in risk assessment. This study introduces a novel three-channel shear horizontal surface acoustic wave (SH-SAW) biosensor for point-of-care testing (POCT) of CVD biomarkers. Utilizing a reflected-type sensor design, the system achieves high sensitivity and low noise by optimizing the reflector arrangement, reducing signal loss and production costs. The biosensor simultaneously detects ApoA1 and ApoB using independent sensing channels, with one channel as a reference. Its compact <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3 \text{mm} \times 5 \text{mm}$</tex> chip integrates epoxy and glass protection to ensure durability and liquid resistance. The platform employs real-time slope signal analysis for rapid detection of lipid profiles, eliminating the need for secondary enhancement even at high analyte concentrations. Comparative studies reveal strong correlations with clinical results <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(R=0.965$</tex> for <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$A p o B$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R=0.890$</tex> for ApoA1) and detection limits of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8.01 \text{mg} / \text{dL}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$6.597 \text{mg} / \text{dL}$</tex>, respectively. These advancements position the SH-SAW biosensor as a rapid, cost-effective, and portable solution for personalized health management and preventive medicine.