Frizzled receptor 5 (FzD5) is a significant protein receptor in the Wingless/Int-1 (WNT) signaling pathway, which plays a crucial role in the genesis and development of breast cancer. Here, we constructed a biosensor based on Inducible positive amplification regulation (IPAR) amplification mode coupled with the Double-strand Specific Nuclease (DSN) for sensitive detection of FzD5 mRNA. IPAR as a mode of gene expression regulation in prokaryotes, organically integrated the Rolling circle amplification (RCA) and strand displacement amplification (SDA) for improving amplification efficiency. By clever design, the RCA and SDA cycles were linked to each other to produce large amounts of single-stranded DNA (ssDNA). And DSN as a terminal signal output sheared perfectly paired double-stranded DNA (dsDNA) of probes and ssDNA, greatly improving the specificity of the biosensor. Taking full advantage of the IPAR mode with high amplification efficiency, the detection limit of the biosensor was as low as 99 fM. Therefore, the biosensor was a promising tool in the detection of cancer markers. And it provided new ideas for RCA and SDA applications and new application value for IPAR mode.

中文翻译：

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诱导型阳性扩增调节与双链特异性核酸酶偶联用于 FzD5 mRNA 检测


卷曲受体 5 （FzD5） 是 Wingless/Int-1 （WNT） 信号通路中的重要蛋白受体，在乳腺癌的发生和发展中起着至关重要的作用。在这里，我们构建了一个基于诱导型正扩增调节 （IPAR） 扩增模式与双链特异性核酸酶 （DSN） 耦合的生物传感器，用于灵敏检测 FzD5 mRNA。IPAR 作为原核生物基因表达调控的一种模式，有机地整合了滚环扩增 （RCA） 和链置换扩增 （SDA），以提高扩增效率。通过巧妙的设计，RCA 和 SDA 循环相互连接以产生大量单链 DNA （ssDNA）。而 DSN 作为末端信号输出剪切了双链 DNA （dsDNA） 的探针和 ssDNA 完美配对，大大提高了生物传感器的特异性。充分利用扩增效率高的 IPAR 模式，生物传感器的检测限低至 99 fM。因此，生物传感器是检测癌症标志物的一种很有前途的工具。它为 RCA 和 SDA 应用提供了新的想法，并为 IPAR 模式提供了新的应用价值。