Inverse opal microneedles arrays for fluorescence enhanced screening skin interstitial fluid biomarkers

Infectious diseases caused by bacteria have become serious health concerns. Efficient and sensitive early detections are of pivotal significance in the diagnosis and treatment of bacterial infection. Here, we develop novel inverse opal microneedles (MNs) arrays for in situ extraction and fluorescence-enhanced detection of target biomarkers in skin interstitial fluid (ISF). As the MNs array is fabricated by applying a resin to replicate the colloidal crystal-filled negative mold , it possesses the exceptional arranged porous structure and unique photonic band gap (PBG) properties. Benefitting from these features, the inverse opal MNs array enables non-invasive skin ISF sampling and provides enhanced fluorescence signal intensity towards specific bio-probes, facilitating improved detection sensitivity. On the basis of the inverse opal MNs array, we have further verified its value of in situ extraction and fluorescence-enhanced detection of lipopolysaccharide (LPS) with high efficiency and sensitivity in skin ISF from infected rats. These results indicate the great potential value of the inverse opal MNs array in non-invasive clinical diagnosis and other related biomedical applications .