Recently, prenatal diagnosis with non-invasive insight is a progressive approach in clinical medicine to prevent the birth of infants with genetic abnormalities. Cell free fetal DNA (cffDNA) makes up approximately 3–6% of the bare DNA in the mother's bloodstream which is produced during pregnancy and can be used to detect fetal sex and disease in the early stages. SRY is a gene located on the chromosome Y which determines the sex of male infants. In this work, a new nanobiosensor based on the fluorescence property of r-GQD@HTAB (reduced graphene quantum dots modified with hexadecyl trimethyl ammonium bromide) was fabricated that can identify the SRY gene in cffDNA with high sensitivity and specificity. A detection limit of 0.082 nM and the linear response range of 0.16–1.5 nM was obtained for the method. It was able to discriminate the target sequence with high specificity from the non-target sequences. This biosensor includes a new graphene quantum dot modified with a surfactant, HTAB which leads to high fluorescence emission of it and then more precise differentiation between ssDNA and DsDNA in a solution. In conclusion, it provides a novel analytical tool for detection of small amount of DNA and fetal sex and genetic diseases in early stage with prenatal and noninvasive tests and applicable for clinical use.

最近，具有非侵入性洞察力的产前诊断是临床医学中预防遗传异常婴儿出生的一种进步方法。无细胞胎儿 DNA (cffDNA) 约占母亲血液中裸露 DNA 的 3-6%，这是在怀孕期间产生的，可用于早期检测胎儿性别和疾病。SRY是位于Y染色体上的一个基因，它决定了男婴的性别。在这项工作中，基于r-GQD@HTAB（用十六烷基三甲基溴化铵修饰的还原石墨烯量子点）的荧光特性，制造了一种新型纳米生物传感器，可以高灵敏度和特异性地识别cffDNA中的SRY基因。该方法的检测限为 0.082 nM，线性响应范围为 0.16-1.5 nM。它能够以高特异性将目标序列与非目标序列区分开来。这种生物传感器包括一个用表面活性剂 HTAB 修饰的新型石墨烯量子点，这会导致它的高荧光发射，然后在溶液中更精确地区分 ssDNA 和 DsDNA。总之，它为产前和无创检测的早期检测少量DNA和胎儿性别和遗传疾病提供了一种新的分析工具，适用于临床。