DETEKSI UAP SAFROL MENGGUNAKAN SENSOR BERBASIS QUARTZ CRYSTAL MICROBALANCE (QCM) BERLAPIS KITOSAN

NAWA YUNIA EKARIYANI, Dr. Kuwat Triyana, Dr. Roto, M.Eng

2017 | Tesis | S2 Ilmu Fisika

Telah dilakukan deteksi uap safrol menggunakan sensor Quartz Crystal Microbalance (QCM) berlapis kitosan. Kitosan dilapiskan di atas permukaan QCM yang telah dilapisi dengan L-cysteine melalui metode Self-Assembly Monolayer (SAM) dan glutaraldehyde sebagai perekat. Cairan safrol dipanaskan hingga suhunya mencapai 85 derajat Celcius kemudian uapnya dialirkan melalui selang ke dalam ruang sensor. Ruang sensor berisi dua keping QCM, yaitu QCM kosong dan QCM berlapis kitosan serta sensor suhu. Frekuensi QCM dideteksi menggunakan sensor gas (uap) dan diamati perubahannya ketika dipapar dengan uap safrol. Variasi volume safrol yang dideteksi sebesar 4-20 mikroliter dengan ruang sampel bervolume 30 mililiter. Hasil deteksi memperlihatkan besarnya perubahan frekuensi QCM sebanding dengan pertambahan volume safrol. Perubahan frekuensi pada QCM kosong berkisar antara 28-53 Hz sedangkan QCM berlapis kitosan sekitar 304-776 Hz. Hal ini menandakan bahwa pelapisan kitosan di atas permukaan QCM mampu meningkatkan kemampuan deteksi sensor karena adanya ikatan hidrogen antara kitosan dan safrol. Sensitivitas sensor dihitung dari besarnya rerata perubahan frekuensi QCM sebelum dan setelah dilapisi dengan kitosan. Sensitivitas rerata QCM sebelum dilapisi kitosan sebesar 42,59 Hz, dan setelah dilapisi kitosan sebesar 648,16 Hz.

The detection of safrole vapour has been done using Quartz Crystal Microbalance (QCM) sensor coated chitosan. Chitosan coated on the QCM surface that has been coated with L-cysteine using Self-Assembly Monolayer (SAM) method and glutaraldehyde as coupling agent. Safrole liquid heated until its temperature reach 85 degree Celcius then vapours steered into sensor chamber. Sensor chamber contains of two plates of QCM, QCM blank and QCM coated chitosan, and temperature sensor. QCM frequency has been detected using gas (vapour) sensor and its frequency shift observed when its affected by safrole vapour. Safrole volume 4-20 microliter has been detected with volume of sample chamber is 30 mililiter. The detection results show that frequency shift equal with the increase of safrole volume. Frequency shift of QCM Blank is 28-53 Hz and QCM coated chitosan is 304-776 Hz. This is prooving that chitosan layer on the QCM surface can improve the sensor's detection because of hydrogen bond between chitosan and safrole. Sensor sensitivity measured from the average of QCM frequency shift before and after coated by chitosan. The average sensitivity of QCM sensor before coated is 42,59 Hz and after coated is 648,16 Hz.

Kata Kunci : Quartz Crystal Microbalance (QCM), safrole, chitosan, Self-Assembly Monolayer (SAM)