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Updated: Jun 30, 2026

Hollow Microneedle-based Sensor for Multiplexed Transdermal Electrochemical Sensing
Published on: June 1, 2012
In Vivo Monitoring of Thrombo-Inflammatory Biomarkers via Molecularly Imprinted Polymer-Integrated Hydrogel
Mahmoud Ayman Saleh1, Peyman GhavamiNejad2,3, Arash Khorrami Jahromi1
1Department of Bioengineering, McGill University, Montreal, Quebec, Canada.
Abstract:
Thrombotic disorders are a leading cause of cardiovascular mortality worldwide; however, real-time, point-of-care monitoring technologies for timely detection of evolving coagulopathies remain inaccessible. Wearable, minimally invasive tracking of thrombo-inflammatory activity could enable earlier risk assessment and more effective therapy monitoring than conventional episodic blood tests. Here, we present a reagent-free, wearable electrochemical platform that integrates an on-chip Prussian Blue (PB) redox transducer with a signal-off molecularly imprinted polymer (MIP) layer and a biocompatible hydrogel microneedle (HMN) array for interstitial fluid (ISF) sampling, enabling direct electrochemical detection of thrombo-inflammatory biomarkers. The electrochemical PB/MIP (e-MIP) biosensor was configured to quantify thrombin (thrombotic biomarker) as well as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) (inflammatory biomarkers) directly in dermal ISF extracted via the integrated HMNs. The wearable e-MIP was characterized in vitro and ex vivo, where porcine skin tests preserved linearity and achieved limits of detection (LODs) of 0.26 ng mL- 1 for thrombin and ≤ 0.41 pg mL- 1 for IL-6 and TNF-α, confirming sensitive performance in a skin model. Also, selectivity studies against potential interferents (e.g., prothrombin or cardiac troponins) were conducted to assess the possible cross-reactivity. in vivo, HMN-integrated patches applied to lipopolysaccharide (LPS)-challenged rats sampled ISF and delivered it to the e-MIP, which captured the rise-and-fall kinetics of thrombin and IL-6 over 0-24 h. The results were validated against parallel enzyme-linked immunosorbent assays (ELISAs) performed on plasma collected at corresponding time points. Its versatile architecture and demonstrated in vivo performance position it as a promising platform that can enable early thrombotic risk assessment and therapeutic monitoring, with potential applications in personalized cardiovascular management following clinical validation.

