An affibody-conjugated nanoprobe for IGF-1R targeted cancer fluorescent and photoacoustic dual-modality imaging.

Dual-modal molecular imaging that combines photoacoustic imaging (PAI) with near-infrared fluorescence (NIRF) imaging integrates the benefits of both imaging modalities and may achieve more precise detection of disease. In this study, silver sulfide quantum dots (Ag2S QDs) with superior photoacoustic properties and a strong fluorescent emission in the NIR region were successfully synthesized. They were further modified with the insulin-like growth factor 1 receptor (IGF-1R) targeted small scaffold protein, Affibody (ZIGF-1) to achieved targeted photoacoustic/fluorescent dual-modal imaging of cancer. Our results showed that the prepared nanoprobe had good tumor targeting properties in vivo, and the probe also showed good biocompatibility without any significant toxicity.